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  • SQL SERVER – Weekly Series – Memory Lane – #050

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Executing Remote Stored Procedure – Calling Stored Procedure on Linked Server In this example we see two different methods of how to call Stored Procedures remotely.  Connection Property of SQL Server Management Studio SSMS A very simple example of the how to build connection properties for SQL Server with the help of SSMS. Sample Example of RANKING Functions – ROW_NUMBER, RANK, DENSE_RANK, NTILE SQL Server has a total of 4 ranking functions. Ranking functions return a ranking value for each row in a partition. All the ranking functions are non-deterministic. T-SQL Script to Add Clustered Primary Key Jr. DBA asked me three times in a day, how to create Clustered Primary Key. I gave him following sample example. That was the last time he asked “How to create Clustered Primary Key to table?” 2008 2008 – TRIM() Function – User Defined Function SQL Server does not have functions which can trim leading or trailing spaces of any string at the same time. SQL does have LTRIM() and RTRIM() which can trim leading and trailing spaces respectively. SQL Server 2008 also does not have TRIM() function. User can easily use LTRIM() and RTRIM() together and simulate TRIM() functionality. http://www.youtube.com/watch?v=1-hhApy6MHM 2009 Earlier I have written two different articles on the subject Remove Bookmark Lookup. This article is as part 3 of original article. Please read the first two articles here before continuing reading this article. Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 2 Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 3 Interesting Observation – Query Hint – FORCE ORDER SQL Server never stops to amaze me. As regular readers of this blog already know that besides conducting corporate training, I work on large-scale projects on query optimizations and server tuning projects. In one of the recent projects, I have noticed that a Junior Database Developer used the query hint Force Order; when I asked for details, I found out that the basic concept was not properly understood by him. Queries Waiting for Memory Allocation to Execute In one of the recent projects, I was asked to create a report of queries that are waiting for memory allocation. The reason was that we were doubtful regarding whether the memory was sufficient for the application. The following query can be useful in similar cases. Queries that do not have to wait on a memory grant will not appear in the result set of following query. 2010 Quickest Way to Identify Blocking Query and Resolution – Dirty Solution As the title suggests, this is quite a dirty solution; it’s not as elegant as you expect. However, it works totally fine. Simple Explanation of Data Type Precedence While I was working on creating a question for SQL SERVER – SQL Quiz – The View, The Table and The Clustered Index Confusion, I had actually created yet another question along with this question. However, I felt that the one which is posted on the SQL Quiz is much better than this one because what makes that more challenging question is that it has a multiple answer. Encrypted Stored Procedure and Activity Monitor I recently had received questionable if any stored procedure is encrypted can we see its definition in Activity Monitor.Answer is - No. Let us do a quick test. Let us create following Stored Procedure and then launch the Activity Monitor and check the text. Indexed View always Use Index on Table A single table can have maximum 249 non clustered indexes and 1 clustered index. In SQL Server 2008, a single table can have maximum 999 non clustered indexes and 1 clustered index. It is widely believed that a table can have only 1 clustered index, and this belief is true. I have some questions for all of you. Let us assume that I am creating view from the table itself and then create a clustered index on it. In my view, I am selecting the complete table itself. 2011 Detecting Database Case Sensitive Property using fn_helpcollations() I received a question on how to determine the case sensitivity of the database. The quick answer to this is to identify the collation of the database and check the properties of the collation. I have previously written how one can identify database collation. Once you have figured out the collation of the database, you can put that in the WHERE condition of the following T-SQL and then check the case sensitivity from the description. Server Side Paging in SQL Server CE (Compact Edition) SQL Server Denali is coming up with new T-SQL of Paging. I have written about the same earlier.SQL SERVER – Server Side Paging in SQL Server Denali – A Better Alternative,  SQL SERVER – Server Side Paging in SQL Server Denali Performance Comparison, SQL SERVER – Server Side Paging in SQL Server Denali – Part2 What is very interesting is that SQL Server CE 4.0 have the same feature introduced. Here is the quick example of the same. To run the script in the example, you will have to do installWebmatrix 4.0 and download sample database. Once done you can run following script. Why I am Going to Attend PASS Summit Unite 2011 The four-day event will be marked by a lot of learning, sharing, and networking, which will help me increase both my knowledge and contacts. Every year, PASS Summit provides me a golden opportunity to build my network as well as to identify and meet potential customers or employees. 2012 Manage Help Settings – CTRL + ALT + F1 This is very interesting read as my daughter once accidently came across a screen in SQL Server Management Studio. It took me 2-3 minutes to figure out how she has created the same screen. Recover the Accidentally Renamed Table “I accidentally renamed table in my SSMS. I was scrolling very fast and I made mistakes. It was either because I double clicked or clicked on F2 (shortcut key for renaming). However, I have made the mistake and now I have no idea how to fix this. If you have renamed the table, I think you pretty much is out of luck. Here are few things which you can do which can give you an idea about what your table name can be if you are lucky. Identify Numbers of Non Clustered Index on Tables for Entire Database Here is the script which will give you numbers of non clustered indexes on any table in entire database. Identify Most Resource Intensive Queries – SQL in Sixty Seconds #029 – Video Here is the complete complete script which I have used in the SQL in Sixty Seconds Video. Thanks Harsh for important Tip in the comment. http://www.youtube.com/watch?v=3kDHC_Tjrns Advanced Data Quality Services with Melissa Data – Azure Data Market For the purposes of the review, I used a database I had in an Excel spreadsheet with name and address information. Upon a cursory inspection, there are miscellaneous problems with these records; some addresses are missing ZIP codes, others missing a city, and some records are slightly misspelled or have unparsed suites. With DQS, I can easily add a knowledge base to help standardize my values, such as for state abbreviations. But how do I know that my address is correct? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Modern/Metro Internet Explorer: What were they thinking???

    - by Rick Strahl
    As I installed Windows 8.1 last week I decided that I really should take a closer look at Internet Explorer in the Modern/Metro environment again. Right away I ran into two issues that are real head scratchers to me.Modern Split Windows don't resize Viewport but Zoom OutThis one falls in the "WTF, really?" department: It looks like Modern Internet Explorer's Modern doesn't resize the browser window as every other browser (including IE 11 on the desktop) does, but rather tries to adjust the zoom to the width of the browser. This means that if you use the Modern IE browser and you split the display between IE and another application, IE will be zoomed out, with text becoming much, much smaller, rather than resizing the browser viewport and adjusting the pixel width as you would when a browser window is typically resized.Here's what I'm talking about in a couple of pictures. First here's the full screen Internet Explorer version (this shot is resized down since it's full screen at 1080p, click to see the full image):This brings up the first issue which is: On the desktop who wants to browse a site full screen? Most sites aren't fully optimized for 1080p widescreen experience and frankly most content that wide just looks weird. Even in typical 10" resolutions of 1280 width it's weird to look at things this way. At least this issue can be worked around with @media queries and either constraining the view, or adding additional content to make use of the extra space. Still running a desktop browser full screen is not optimal on a desktop machine - ever.Regardless, this view, while oversized, is what I expect: Everything is rendered in the right ratios, with font-size and the responsive design styling properly respected.But now look what happens when you split the desktop windows and show half desktop and have modern IE (this screen shot is not resized but cropped - this is actual size content as you can see in the cropped Twitter window on the right half of the screen):What's happening here is that IE is zooming out of the content to make it fit into the smaller width, shrinking the content rather than resizing the viewport's pixel width. In effect it looks like the pixel width stays at 1080px and the viewport expands out height-wise in response resulting in some crazy long portrait view.There goes responsive design - out the window literally. If you've built your site using @media queries and fixed viewport sizes, Internet Explorer completely screws you in this split view. On my 1080p monitor, the site shown at a little under half width becomes completely unreadable as the fonts are too small and break up. As you go into split view and you resize the window handle the content of the browser gets smaller and smaller (and effectively longer and longer on the bottom) effectively throwing off any responsive layout to the point of un-readability even on a big display, let alone a small tablet screen.What could POSSIBLY be the benefit of this screwed up behavior? I checked around a bit trying different pages in this shrunk down view. Other than the Microsoft home page, every page I went to was nearly unreadable at a quarter width. The only page I found that worked 'normally' was the Microsoft home page which undoubtedly is optimized just for Internet Explorer specifically.Bottom Address Bar opaquely overlays ContentAnother problematic feature for me is the browser address bar on the bottom. Modern IE shows the status bar opaquely on the bottom, overlaying the content area of the Web Page - until you click on the page. Until you do though, the address bar overlays the bottom content solidly. And not just a little bit but by good sizable chunk.In the application from the screen shot above I have an application toolbar on the bottom and the IE Address bar completely hides that bottom toolbar when the page is first loaded, until the user clicks into the content at which point the address bar shrinks down to a fat border style bar with a … on it. Toolbars on the bottom are pretty common these days, especially for mobile optimized applications, so I'd say this is a common use case. But even if you don't have toolbars on the bottom maybe there's other fixed content on the bottom of the page that is vital to display. While other browsers often also show address bars and then later hide them, these other browsers tend to resize the viewport when the address bar status changes, so the content can respond to the size change. Not so with Modern IE. The address bar overlays content and stays visible until content is clicked. No resize notification or viewport height change is sent to the browser.So basically Internet Explorer is telling me: "Our toolbar is more important than your content!" - AND gives me no chance to re-act to that behavior. The result on this page/application is that the user sees no actionable operations until he or she clicks into the content area, which is terrible from a UI perspective as the user has no idea what options are available on initial load.It's doubly confounding in that IE is running in full screen mode and has an the entire height of the screen at its disposal - there's plenty of real estate available to not require this sort of hiding of content in the first place. Heck, even Windows Phone with its more constrained size doesn't hide content - in fact the address bar on Windows Phone 8 is always visible.What were they thinking?Every time I use anything in the Modern Metro interface in Windows 8/8.1 I get angry.  I can pretty much ignore Metro/Modern for my everyday usage, but unfortunately with Internet Explorer in the modern shell I have to live with, because there will be users using it to access my sites. I think it's inexcusable by Microsoft to build such a crappy shell around the browser that impacts the actual usability of Web content. In both of the cases above I can only scratch my head at what could have possibly motivated anybody designing the UI for the browser to make these screwed up choices, that manipulate the content in a totally unmaintainable way.© Rick Strahl, West Wind Technologies, 2005-2013Posted in Windows  HTML5   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • WhatsApp &amp; Tasker for Android &ndash; Read &amp; Write messages

    - by Shaurya Anand
    So, I finally gave up on all my previous the Microsoft Mobile/Phone OS devices and made my switch to Android this year. I am using my Samsung Galaxy Note GT-N7000 with CyanogenMod 9.1.0 (http://get.cm/get/jenkins/7086/cm-9.1.0-n7000.zip) and ClockworkMod 6.0.1.2 (http://download2.clockworkmod.com/recoveries/recovery-clockwork-6.0.1.2-n7000.zip) since August this year and I am so happy with the performance and the flexibility it offers me. As a software developer by profession, I would expect most of my gadget to be highly customizable and programmable (one time or at intervals) to suit my needs as close as it can. I was introduced to Automation for Android – Tasker (https://play.google.com/store/apps/details?id=net.dinglisch.android.taskerm&hl=en) via reddit (http://www.reddit.com/r/tasker) and the word ‘automation’ was enough for me to dive right into this app. Only automation that I did earlier was switching profiles depending on location on there phones. And now, just imagine a complete set of possibilities that can be automate on the phone or via the phone. I did my research and found a couple of other tools that do the same/as close as what Tasker can do and few of them are even free. There’s one even by Microsoft called on{X} (https://play.google.com/store/apps/details?id=com.microsoft.onx.app&hl=en). Microsoft’s on{X} really caught my eye. You can write code for your phone on the web application by them, deploy it on your phone and even trace the flow all using your PC. Really brilliant, I love the fact that it’s all JavaScript. Here comes the but, it is still very very young and it’s policy of accessing my News Feed on Facebook is not something that I can not digest. On{X} is good, but as I said earlier, the API is not very mature and hence, I gave up on it. I bought Tasker, the best 5,00 € I spent in ages and I want to talk about it in this post. I am still a “noob” while operating this tool, but I tried my shot at automating WhatsApp (https://play.google.com/store/apps/details?id=com.whatsapp&hl=en), a popular messenger for various platform. The requirement for the automation is that, if I send a WhatsApp ‘wru’ message to the phone, it should respond back giving the location and battery level of my phone. It could be useful, if you like to locate your misplaced phone or automatically reply to your partner/friend, honestly, I don’t know what you will use it - through this post, I am just introducing automating WhatsApp using Tasker. Before we begin, the following script only works when your phone is rooted as we will be accessing the WhatsApp database and type some special characters like ‘:’. Let’s follow the code line by line: Profile:         Location request from XYZ. (12) // Name of your profile. Event:         Notification [ Owner Application:WhatsApp Title:* ] // When a new notification comes from WhatsApp, this event is fired. Read the end note, if you face problems with Chrome app after enabling Tasker accessibility. Enter:         A1: Run Shell [ Command:sqlite3 // We will access the WhatsApp database and check if the message comes from designated phone number or not. We mustn’t reply to every message.                 /data/data/com.whatsapp/databases/msgstore.db "SELECT _id, data FROM                  messages WHERE key_from_me='0' AND key_remote_jid LIKE '%XXXXXXXXXXX%' // Replace XXXXXXXXXXX with the phone number of your message sender.                 ORDER BY _id DESC LIMIT 1;" Timeout (Seconds):10 Use Root:On Store // I made a timeout for 10 seconds, if in case WhatsApp is busy accessing the database.                 Result In:%WHATSAPP_CURRREQ ] // Store the read Id and the last message on to the variable %WHATSAPP_CURRREQ         A2: If [ %WHATSAPP_CURRREQ ~R .*[wW][rR][uU].* ] // Check if the pattern of the message is correct and we are all set to send the location.                 A3: If [ %WHATSAPP_CURRREQ !~ %WHATSAPP_LASTREQ ] // Verify that the message is different from the last request. Remember every message has a unique Id.                         A4: Notify [ Title:WhatsApp location request... Text:Sending location // Just a notification that the location message is being prepared.                                 to Krati Gupta... Icon:<icon> Number:0 Permanent:On Priority:3 ] // Make a note it is a permanent notification, we will clear it later.                         A5: Secure Settings [ Configuration:Pattern Lock Disabled // I am disabling the pattern lock, that I use using the plugin Secure Settings.                                 Package:com.intangibleobject.securesettings.plugin Name:Secure // You can download the plugin from here: https://play.google.com/store/apps/details?id=com.intangibleobject.securesettings.plugin&hl=en                                 Settings ]                         A6: Secure Settings [ Configuration:Keyguard Disabled // Disable the keygaurd, it is useful, when your phone is on lock and you want to automate everything, even the typing.                                 Package:com.intangibleobject.securesettings.plugin Name:Secure                                 Settings ]                         A7: Secure Settings [ Configuration:GPS Enabled // Pretty clear, turn on the GPS and get location at A8                                 Package:com.intangibleobject.securesettings.plugin Name:Secure                                 Settings ]                         A8: AutoShortcut [ Configuration:WhatsApp: Some One // I am using AutoShortcut plugin (https://play.google.com/store/apps/details?id=com.joaomgcd.autoshortcut) to start WhatsApp with the indented recipient.                                 Package:com.joaomgcd.autoshortcut Name:AutoShortcut ] // Replace Some One, actually choose it from the plugin, the right recipient.                         A9: Get Location [ Source:Any Timeout (Seconds):30 Continue Task // I am getting the location, timeout is 30 seconds, adjust it accordingly.                                 Immediately:Off Keep Tracking:Off ]                         A10: Secure Settings [ Configuration:Screen Dim // Now, this extension of the plugin Secure Settings, wakes your device so that you can type out the string on the WhatsApp app.                                 5 Seconds Package:com.intangibleobject.securesettings.plugin                                 Name:Secure Settings ]                         A11: Run Shell [ Command:input text // Now, I am using the shell script to type the text to the window, because the ‘:’ while not be typed from the Type task in Tasker.                                 LOCATION:maps.google.com/maps?q=%LOC Timeout (Seconds):0 Use Root:On // And also, this is way faster, but remember you need root for this, not for the other way of typing.                                 Store Result In: ]                         A12: Dpad [ Button:Right Repeat Times:1 ] // Focus the Send button                         A13: Dpad [ Button:Press Repeat Times:1 ] // And press it.                         A14: Dpad [ Button:Left Repeat Times:1 ] // Get back to the typing box.                         A15: Run Shell [ Command:input text LOCATION_ACCURACY:%LOCACC Timeout                                 (Seconds):0 Use Root:On Store Result In: ]                         A16: Dpad [ Button:Right Repeat Times:1 ]                         A17: Dpad [ Button:Press Repeat Times:1 ]                         A18: Dpad [ Button:Left Repeat Times:1 ]                         A19: Run Shell [ Command:input text BATTERY_LEVEL:%BATT% Timeout // I am adding Battery level in my case as well.                                 (Seconds):0 Use Root:On Store Result In: ]                         A20: Dpad [ Button:Right Repeat Times:1 ]                         A21: Dpad [ Button:Press Repeat Times:1 ]                         A22: Variable Set [ Name:%WHATSAPP_LASTREQ To:%WHATSAPP_CURRREQ Do // And now, we say, request is done.                                 Maths:Off Append:Off ]                         A23: Button [ Button:Back ] // I am exiting the WhatsApp nicely and not killing it. If you are the murderer kind, kill it, just know, you don’t have any place in the heaven.                         A24: Button [ Button:Back ]                         A25: Notify Cancel [ Title: Warn Not Exist:Off ] // Remove the permanent notification.                         A26: Notify [ Title:WhatsApp location request Text:Location sent // Make a temporary notification, and say, location is sent.                                 successfully. Icon:<icon> Number:0 Permanent:Off Priority:3 ]                                                         A27: Secure Settings [ Configuration:GPS Disabled // Disable all the horrible things we turned on earlier.                                 Package:com.intangibleobject.securesettings.plugin Name:Secure                                 Settings ]                         A28: Secure Settings [ Configuration:Pattern Lock Enabled                                 Package:com.intangibleobject.securesettings.plugin Name:Secure                                 Settings ]                         A29: Secure Settings [ Configuration:Keyguard Enabled                                 Package:com.intangibleobject.securesettings.plugin Name:Secure                                 Settings ]                 A30: End If         A31: End If Download this Task from here: http://db.tt/9vRmbhyb That’s it in the above small example – you can read/write messages from/to WhatsApp app. I am using n7000-cm9.1-cwr6. Oh yea, and if you are having the Talkback auto enabled for Chrome browser, you need to turn Off the Web scripts to run. Tasker is amazing, I have automated a lot of tasks using this tool. I will share a few none generic ones with you in my coming post here.

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  • tile_static, tile_barrier, and tiled matrix multiplication with C++ AMP

    - by Daniel Moth
    We ended the previous post with a mechanical transformation of the C++ AMP matrix multiplication example to the tiled model and in the process introduced tiled_index and tiled_grid. This is part 2. tile_static memory You all know that in regular CPU code, static variables have the same value regardless of which thread accesses the static variable. This is in contrast with non-static local variables, where each thread has its own copy. Back to C++ AMP, the same rules apply and each thread has its own value for local variables in your lambda, whereas all threads see the same global memory, which is the data they have access to via the array and array_view. In addition, on an accelerator like the GPU, there is a programmable cache, a third kind of memory type if you'd like to think of it that way (some call it shared memory, others call it scratchpad memory). Variables stored in that memory share the same value for every thread in the same tile. So, when you use the tiled model, you can have variables where each thread in the same tile sees the same value for that variable, that threads from other tiles do not. The new storage class for local variables introduced for this purpose is called tile_static. You can only use tile_static in restrict(direct3d) functions, and only when explicitly using the tiled model. What this looks like in code should be no surprise, but here is a snippet to confirm your mental image, using a good old regular C array // each tile of threads has its own copy of locA, // shared among the threads of the tile tile_static float locA[16][16]; Note that tile_static variables are scoped and have the lifetime of the tile, and they cannot have constructors or destructors. tile_barrier In amp.h one of the types introduced is tile_barrier. You cannot construct this object yourself (although if you had one, you could use a copy constructor to create another one). So how do you get one of these? You get it, from a tiled_index object. Beyond the 4 properties returning index objects, tiled_index has another property, barrier, that returns a tile_barrier object. The tile_barrier class exposes a single member, the method wait. 15: // Given a tiled_index object named t_idx 16: t_idx.barrier.wait(); 17: // more code …in the code above, all threads in the tile will reach line 16 before a single one progresses to line 17. Note that all threads must be able to reach the barrier, i.e. if you had branchy code in such a way which meant that there is a chance that not all threads could reach line 16, then the code above would be illegal. Tiled Matrix Multiplication Example – part 2 So now that we added to our understanding the concepts of tile_static and tile_barrier, let me obfuscate rewrite the matrix multiplication code so that it takes advantage of tiling. Before you start reading this, I suggest you get a cup of your favorite non-alcoholic beverage to enjoy while you try to fully understand the code. 01: void MatrixMultiplyTiled(vector<float>& vC, const vector<float>& vA, const vector<float>& vB, int M, int N, int W) 02: { 03: static const int TS = 16; 04: array_view<const float,2> a(M, W, vA); 05: array_view<const float,2> b(W, N, vB); 06: array_view<writeonly<float>,2> c(M,N,vC); 07: parallel_for_each(c.grid.tile< TS, TS >(), 08: [=] (tiled_index< TS, TS> t_idx) restrict(direct3d) 09: { 10: int row = t_idx.local[0]; int col = t_idx.local[1]; 11: float sum = 0.0f; 12: for (int i = 0; i < W; i += TS) { 13: tile_static float locA[TS][TS], locB[TS][TS]; 14: locA[row][col] = a(t_idx.global[0], col + i); 15: locB[row][col] = b(row + i, t_idx.global[1]); 16: t_idx.barrier.wait(); 17: for (int k = 0; k < TS; k++) 18: sum += locA[row][k] * locB[k][col]; 19: t_idx.barrier.wait(); 20: } 21: c[t_idx.global] = sum; 22: }); 23: } Notice that all the code up to line 9 is the same as per the changes we made in part 1 of tiling introduction. If you squint, the body of the lambda itself preserves the original algorithm on lines 10, 11, and 17, 18, and 21. The difference being that those lines use new indexing and the tile_static arrays; the tile_static arrays are declared and initialized on the brand new lines 13-15. On those lines we copy from the global memory represented by the array_view objects (a and b), to the tile_static vanilla arrays (locA and locB) – we are copying enough to fit a tile. Because in the code that follows on line 18 we expect the data for this tile to be in the tile_static storage, we need to synchronize the threads within each tile with a barrier, which we do on line 16 (to avoid accessing uninitialized memory on line 18). We also need to synchronize the threads within a tile on line 19, again to avoid the race between lines 14, 15 (retrieving the next set of data for each tile and overwriting the previous set) and line 18 (not being done processing the previous set of data). Luckily, as part of the awesome C++ AMP debugger in Visual Studio there is an option that helps you find such races, but that is a story for another blog post another time. May I suggest reading the next section, and then coming back to re-read and walk through this code with pen and paper to really grok what is going on, if you haven't already? Cool. Why would I introduce this tiling complexity into my code? Funny you should ask that, I was just about to tell you. There is only one reason we tiled our extent, had to deal with finding a good tile size, ensure the number of threads we schedule are correctly divisible with the tile size, had to use a tiled_index instead of a normal index, and had to understand tile_barrier and to figure out where we need to use it, and double the size of our lambda in terms of lines of code: the reason is to be able to use tile_static memory. Why do we want to use tile_static memory? Because accessing tile_static memory is around 10 times faster than accessing the global memory on an accelerator like the GPU, e.g. in the code above, if you can get 150GB/second accessing data from the array_view a, you can get 1500GB/second accessing the tile_static array locA. And since by definition you are dealing with really large data sets, the savings really pay off. We have seen tiled implementations being twice as fast as their non-tiled counterparts. Now, some algorithms will not have performance benefits from tiling (and in fact may deteriorate), e.g. algorithms that require you to go only once to global memory will not benefit from tiling, since with tiling you already have to fetch the data once from global memory! Other algorithms may benefit, but you may decide that you are happy with your code being 150 times faster than the serial-version you had, and you do not need to invest to make it 250 times faster. Also algorithms with more than 3 dimensions, which C++ AMP supports in the non-tiled model, cannot be tiled. Also note that in future releases, we may invest in making the non-tiled model, which already uses tiling under the covers, go the extra step and use tile_static memory on your behalf, but it is obviously way to early to commit to anything like that, and we certainly don't do any of that today. Comments about this post by Daniel Moth welcome at the original blog.

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  • Cost Comparison Hard Disk Drive to Solid State Drive on Price per Gigabyte - dispelling a myth!

    - by tonyrogerson
    It is often said that Hard Disk Drive storage is significantly cheaper per GiByte than Solid State Devices – this is wholly inaccurate within the database space. People need to look at the cost of the complete solution and not just a single component part in isolation to what is really required to meet the business requirement. Buying a single Hitachi Ultrastar 600GB 3.5” SAS 15Krpm hard disk drive will cost approximately £239.60 (http://scan.co.uk, 22nd March 2012) compared to an OCZ 600GB Z-Drive R4 CM84 PCIe costing £2,316.54 (http://scan.co.uk, 22nd March 2012); I’ve not included FusionIO ioDrive because there is no public pricing available for it – something I never understand and personally when companies do this I immediately think what are they hiding, luckily in FusionIO’s case the product is proven though is expensive compared to OCZ enterprise offerings. On the face of it the single 15Krpm hard disk has a price per GB of £0.39, the SSD £3.86; this is what you will see in the press and this is what sales people will use in comparing the two technologies – do not be fooled by this bullshit people! What is the requirement? The requirement is the database will have a static size of 400GB kept static through archiving so growth and trim will balance the database size, the client requires resilience, there will be several hundred call centre staff querying the database where queries will read a small amount of data but there will be no hot spot in the data so the randomness will come across the entire 400GB of the database, estimates predict that the IOps required will be approximately 4,000IOps at peak times, because it’s a call centre system the IO latency is important and must remain below 5ms per IO. The balance between read and write is 70% read, 30% write. The requirement is now defined and we have three of the most important pieces of the puzzle – space required, estimated IOps and maximum latency per IO. Something to consider with regard SQL Server; write activity requires synchronous IO to the storage media specifically the transaction log; that means the write thread will wait until the IO is completed and hardened off until the thread can continue execution, the requirement has stated that 30% of the system activity will be write so we can expect a high amount of synchronous activity. The hardware solution needs to be defined; two possible solutions: hard disk or solid state based; the real question now is how many hard disks are required to achieve the IO throughput, the latency and resilience, ditto for the solid state. Hard Drive solution On a test on an HP DL380, P410i controller using IOMeter against a single 15Krpm 146GB SAS drive, the throughput given on a transfer size of 8KiB against a 40GiB file on a freshly formatted disk where the partition is the only partition on the disk thus the 40GiB file is on the outer edge of the drive so more sectors can be read before head movement is required: For 100% sequential IO at a queue depth of 16 with 8 worker threads 43,537 IOps at an average latency of 2.93ms (340 MiB/s), for 100% random IO at the same queue depth and worker threads 3,733 IOps at an average latency of 34.06ms (34 MiB/s). The same test was done on the same disk but the test file was 130GiB: For 100% sequential IO at a queue depth of 16 with 8 worker threads 43,537 IOps at an average latency of 2.93ms (340 MiB/s), for 100% random IO at the same queue depth and worker threads 528 IOps at an average latency of 217.49ms (4 MiB/s). From the result it is clear random performance gets worse as the disk fills up – I’m currently writing an article on short stroking which will cover this in detail. Given the work load is random in nature looking at the random performance of the single drive when only 40 GiB of the 146 GB is used gives near the IOps required but the latency is way out. Luckily I have tested 6 x 15Krpm 146GB SAS 15Krpm drives in a RAID 0 using the same test methodology, for the same test above on a 130 GiB for each drive added the performance boost is near linear, for each drive added throughput goes up by 5 MiB/sec, IOps by 700 IOps and latency reducing nearly 50% per drive added (172 ms, 94 ms, 65 ms, 47 ms, 37 ms, 30 ms). This is because the same 130GiB is spread out more as you add drives 130 / 1, 130 / 2, 130 / 3 etc. so implicit short stroking is occurring because there is less file on each drive so less head movement required. The best latency is still 30 ms but we have the IOps required now, but that’s on a 130GiB file and not the 400GiB we need. Some reality check here: a) the drive randomness is more likely to be 50/50 and not a full 100% but the above has highlighted the effect randomness has on the drive and the more a drive fills with data the worse the effect. For argument sake let us assume that for the given workload we need 8 disks to do the job, for resilience reasons we will need 16 because we need to RAID 1+0 them in order to get the throughput and the resilience, RAID 5 would degrade performance. Cost for hard drives: 16 x £239.60 = £3,833.60 For the hard drives we will need disk controllers and a separate external disk array because the likelihood is that the server itself won’t take the drives, a quick spec off DELL for a PowerVault MD1220 which gives the dual pathing with 16 disks 146GB 15Krpm 2.5” disks is priced at £7,438.00, note its probably more once we had two controller cards to sit in the server in, racking etc. Minimum cost taking the DELL quote as an example is therefore: {Cost of Hardware} / {Storage Required} £7,438.60 / 400 = £18.595 per GB £18.59 per GiB is a far cry from the £0.39 we had been told by the salesman and the myth. Yes, the storage array is composed of 16 x 146 disks in RAID 10 (therefore 8 usable) giving an effective usable storage availability of 1168GB but the actual storage requirement is only 400 and the extra disks have had to be purchased to get the  IOps up. Solid State Drive solution A single card significantly exceeds the IOps and latency required, for resilience two will be required. ( £2,316.54 * 2 ) / 400 = £11.58 per GB With the SSD solution only two PCIe sockets are required, no external disk units, no additional controllers, no redundant controllers etc. Conclusion I hope by showing you an example that the myth that hard disk drives are cheaper per GiB than Solid State has now been dispelled - £11.58 per GB for SSD compared to £18.59 for Hard Disk. I’ve not even touched on the running costs, compare the costs of running 18 hard disks, that’s a lot of heat and power compared to two PCIe cards!Just a quick note: I've left a fair amount of information out due to this being a blog! If in doubt, email me :)I'll also deal with the myth that SSD's wear out at a later date as well - that's just way over done still, yes, 5 years ago, but now - no.

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  • Evaluating Solutions to Manage Product Compliance? Don't Wait Much Longer

    - by Kerrie Foy
    Depending on severity, product compliance issues can cause all sorts of problems from run-away budgets to business closures. But effective policies and safeguards can create a strong foundation for innovation, productivity, market penetration and competitive advantage. If you’ve been putting off a systematic approach to product compliance, it is time to reconsider that decision, or indecision. Why now?  No matter what industry, companies face a litany of worldwide and regional regulations that require proof of product compliance and environmental friendliness for market access.  For example, Restriction of Hazardous Substances (RoHS) is a regulation that restricts the use of six dangerous materials used in the manufacture of electronic and electrical equipment.  ROHS was originally adopted by the European Union in 2003 for implementation in 2006, and it has evolved over time through various regional versions for North America, China, Japan, Korea, Norway and Turkey.  In addition, the RoHS directive allowed for material exemptions used in Medical Devices, but that exemption ends in 2014.   Additional regulations worth watching are the Battery Directive, Waste Electrical and Electronic Equipment (WEEE), and Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) directives.  Additional evolving regulations are coming from governing bodies like the Food and Drug Administration (FDA) and the International Organization for Standardization (ISO). Corporate sustainability initiatives are also gaining urgency and influencing product design. In a survey of 405 corporations in the Global 500 by Carbon Disclosure Project, co-written by PwC (CDP Global 500 Climate Change Report 2012 entitled Business Resilience in an Uncertain, Resource-Constrained World), 48% of the respondents indicated they saw potential to create new products and business services as a response to climate change. Just 21% reported a dedicated budget for the research. However, the report goes on to explain that those few companies are winning over new customers and driving additional profits by exploiting their abilities to adapt to environmental needs. The article cites Dell as an example – Dell has invested in research to develop new products designed to reduce its customers’ emissions by more than 10 million metric tons of CO2e per year. This reduction in emissions should save Dell’s customers over $1billion per year as a result! Over time we expect to see many additional companies prove that eco-design provides marketplace benefits through differentiation and direct customer value. How do you meet compliance requirements and also successfully invest in eco-friendly designs? No doubt companies struggle to answer this question. After all, the journey to get there may involve transforming business models, go-to-market strategies, supply networks, quality assurance policies and compliance processes per the rapidly evolving global and regional directives. There may be limited executive focus on the initiative, inability to quantify noncompliance, or not enough resources to justify investment. To make things even more difficult to address, compliance responsibility can be a passionate topic within an organization, making the prospect of change on an enterprise scale problematic and time-consuming. Without a single source of truth for product data and without proper processes in place, ensuring product compliance burgeons into a crushing task that is cost-prohibitive and overwhelming to an organization. With all the overhead, certain markets or demographics become simply inaccessible. Therefore, the risk to consumer goodwill and satisfaction, revenue, business continuity, and market potential is too great not to solve the compliance challenge. Companies are beginning to adapt and even thrive in today’s highly regulated and transparent environment by implementing systematic approaches to product compliance that are more than functional bandages but revenue-generating engines. Consider partnering with Oracle to help you address your compliance needs. Many of the world’s most innovative leaders and pioneers are leveraging Oracle’s Agile Product Lifecycle Management (PLM) portfolio of enterprise applications to manage the product value chain, centralize product data, automate processes, and launch more eco-friendly products to market faster.   Particularly, the Agile Product Governance & Compliance (PG&C) solution provides out-of-the-box functionality to integrate actionable regulatory information into the enterprise product record from the ideation to the disposal/recycling phase. Agile PG&C makes it possible to efficiently manage compliance per corporate green initiatives as well as regional and global directives. Options are critical, but so is ease-of-use. Anyone who’s grappled with compliance policy knows legal interpretation plays a major role in determining how an organization responds to regulation. Agile PG&C gives you the freedom to configure product compliance per your needs, while maintaining rigorous control over the product record in an easy-to-use interface that facilitates adoption efforts. It allows you to assign regulations as specifications for a part or BOM roll-up. Each specification has a threshold value that alerts you to a non-compliance issue if the threshold value is exceeded. Set however many regulations as specifications you need to make sure a product can be sold in your target countries. Another option is to implement like one of our leading consumer electronics customers and define your own “catch-all” specification to ensure compliance in all markets. You can give your suppliers secure access to enter their component data or integrate a third party’s data. With Agile PG&C you are able to design compliance earlier into your products to reduce cost and improve quality downstream when stakes are higher. Agile PG&C is a comprehensive solution that makes product compliance more reliable and efficient. Throughout product lifecycles, use the solution to support full material disclosures, efficiently manage declarations with your suppliers, feed compliance data into a corrective action if a product must be changed, and swiftly satisfy audits by showing all due diligence tracked in one solution. Given the compounding regulation and consumer focus on urgent environmental issues, now is the time to act. Implementing an enterprise, systematic approach to product compliance is a competitive investment. From the start, Agile Product Governance & Compliance enables companies to confidently design for compliance and sustainability, reduce the cost of compliance, minimize the risk of business interruption, deliver responsible products, and inspire new innovation.  Don’t wait any longer! To find out more about Agile Product Governance & Compliance download the data sheet, contact your sales representative, or call Oracle at 1-800-633-0738. Many thanks to Shane Goodwin, Senior Manager, Oracle Agile PLM Product Management, for contributions to this article. 

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  • Are Chromebooks the New Netbooks, and What Does That Mean?

    - by Chris Hoffman
    Netbooks — small, cheap, slow laptops — were once very popular. They fell out of favor — people bought them because they seemed cheap and portable, but the actual experience was lackluster. Most netbooks now sit unused. Windows netbooks have vanished from stores today, but there’s a new super-cheap laptop — the Chromebook. Chromebook sales numbers are impressive, but their usage statistics tell a different story. Are Chromebooks just the new netbook? The Problem With Netbooks Netbooks seemed appealing, especially in an age before tablets and lightweight ultrabooks. You could buy a netbook for $200 or so and have a portable device that let you get on the Internet. The name “netbook” spelled that out — it was a portable device for getting on the ‘net. They weren’t really that great. The original netbook was a lightweight Asus Eee PC that ran Linux alone and had a small amount of fast flash storage. Netbooks eventually ran heavier Windows XP operating systems — Windows Vista was out, but it was just too bloated to run on netbooks. Manufacturers added slow magnetic hard drives, bloatware, and even DVD drives! They couldn’t run most Windows software very well. The build quality was poor and their keyboards were tiny and cramped. People liked the idea of a lightweight device that let them get on the Internet and loved the cheap price, but the actual experience wasn’t great. Chromebook Sales Chromebook sales numbers seem surprisingly high. NPD reported that Chromebooks were 21% of all notebooks sold in the US in 2013. If you combine laptop and tablet sales into a single statistic, Chromebooks were 9.6% of all those devices sold. That’s 2/3 as many Chromebooks sold as iPads in the US! Of Amazon’s best-selling laptop computers, two of the top three are Chromebooks. These definitely look like successful products. Unlike netbooks, Chromebooks are taking off in a big way in the education market. Many schools are buying Chromebooks for their students instead of more expensive Windows laptops. They’re easier to manage and lock down than Windows laptops, but — more importantly for cash-strapped schools — they’re very cheap. Netbooks never had this sort of momentum in schools. Chromebook Usage Statistics Here’s where the rosy picture of Chromebooks starts to become more realistic. StatCounter’s browser usage statistics show how widely used different operating systems are. For example, Windows 7 has the highest share with 35.71% of web activity in April, 2014. The chart doesn’t even show Chrome OS at all, although there is an “Other” number near the bottom. Click the Download Data link to download a CSV file and we can view more detailed information. Chrome OS only accounted for 0.38% of web usage in April, 2014. Desktop Linux, which people often shrug at, accounted for 1.52% in the same month. To its credit, Chrome OS usage has increased. Chromebooks were widely mocked back in November, 2013 when the sales numbers came out. After all, they only accounted for 0.11% of web usage globally in November, 2013! But Chrome OS numbers have been improving: Nov, 2013: 0.11% Dec, 2013: 0.22% Jan, 2014: 0.31% Feb, 2014: 0.35% Mar, 2014: 0.36% Apr, 2014: 0.38% Chrome OS is climbing, but it’s definitely still in the “Other” category. It isn’t as high as we’d expect to see it with those types of sales numbers. Chromebooks vs. Netbooks Chromebooks are more limited devices than traditional PCs. You can do quite a few things, but you have to do it all using Chrome or Chrome apps. Most people won’t be enabling developer mode and installing a Linux desktop. You don’t have access to the powerful desktop software available for Windows and even Mac OS X. On the other hand, these Chromebooks are less compromised than netbooks in many ways. They come with a lightweight operating system designed for portable, mobile devices. They don’t come packed with any bloatware, like the bloatware you’ll find on competing Windows PCs and the original netbooks. They’re cheaper because the manufacturer doesn’t have to pay for a Windows license. There’s no need for antivirus software weighing the operating system down. They’re larger than the original netbooks, with many of them being 11.6-inches instead of the original 8-inch bodies many older netbooks came with. They have larger, more comfortable keyboards and fast solid-state storage. Really, Chromebooks are what netbooks wanted to be. People didn’t buy netbooks to use typical Windows software — they just wanted a lightweight PC. Of course, for many people, the real successor to netbooks is tablets. If all you want is a portable device to throw in a bag so you can get online, maybe a tablet is better. Where Does This Leave Chromebooks? So, are Chromebooks the new netbooks? It’s a bit early to answer that question. Chromebooks are definitely not out of the competition — their sales look good and their usage share is increasing. On the other hand, Chrome OS is still pretty far behind. They’re not catching fire like tablets did. Maybe netbooks were just before their time and Chromebooks were what they were always meant to be. Just as Microsoft’s Windows XP tablets failed, Windows XP netbooks also failed. Tablets took off with a more refined operating system on better hardware years later. “Netbooks” — or Chromebooks — are now taking off with a more purpose-built operating system on better hardware, too. It’s hard to count Chromebooks out because they provide a much better experience than netbooks ever did. If you’re one of the people who wants to use old Windows desktop apps on your portable laptop, you may think netbooks were better — but most people don’t want that. But maybe people either want a full desktop PC experience or a full mobile tablet experience. Is there a place for a laptop with a keyboard that can only view websites? We’ll have to wait and see. Image Credit: Kevin Jarret on Flickr, Clive Darra on Flickr, Sean Freese on Flickr

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  • Clarity is important, both in question and in answer.

    - by gerrylowry
    clarity is important ... i'm often reminded of the Clouseau movie in which Peter Sellers as Chief Inspector Clouseau asks a hotel clerk "Does your dog bite?" ... the clerk answers "no" ... after Clouseau has been bitten by the dog, he looks at the hotel clerk who says "That's not my dog".  Clarity is important, both in question and in answer. i've been a member of forums.asp.net since 2008 ... like many of my peers at forums.asp.net, i've answered my fair share of questions. FWIW, the purpose of this, my first web log post to http://weblogs.asp.net/gerrylowry is to help new members ask better questions and in turn get better answers. TIMTOWTDI  =.  there is more than one way to do it imho, the best way to ask a question in any forum, or even person to person, is to first formulate your question and then ask yourself to answer your own question. Things to consider when asking (the more complete your question, the more likely you'll get the answer you require): -- have you searched Google and/or your favourite search engine(s) before posting your question to forums.asp.net; examples: site:msdn.microsoft.com entity framework 5.0 c#http://lmgtfy.com/?q=site%3Amsdn.microsoft.com+entity+framework+5.0+c%23 site:forums.asp.net MVC tutorial c#http://lmgtfy.com/?q=site%3Aforums.asp.net+MVC+tutorial+c%23 -- are you asking your question in the correct forum?  look at the forums' descriptions at http://forums.asp.net/; examples: Getting Started If you have a general ASP.NET question on a topic that's not covered by one of the other more specific forums - ask it here. MVC Discussions regarding ASP.NET Model-View-Controller (MVC) C# Questions about using C# for ASP.NET development Note:  if your question pertains more to c# than to MVC, choosing the C# forum is likely to be more appropriate. -- is your post subject clear and concise, yet not too vague? compare these three subjects (all three had something to do with GridView):     (1)    please help     (2)    gridview      (3)    How to show newline in GridView  -- have you clearly explained your scenario? compare:  my leg hurts   with   when i walk too much, my right knee hurts in the knee joint  compare:  my code does not work    with    when i enter a date as 2012-11-8, i get a FormatException -- have you checked your spelling, your grammar, and your English? for better or worse, English is the language of forums.asp.net ... many of the currently 170000++ forums.asp.net are not native speakers of English; that's okay ... however, there are times when choosing the more appropriate words will likely get one a better answer; fortunately, there are web tools to help you formulate your question, for example, http://translate.google.com/.  -- have you provided relevant information about your environment? here are a few examples ... feel free to include other items to your question ... rule of thumb:  if you think a given detail is relevant, it likely is -- what technology are you using?    ASP.NET MVC 4, ASP.NET MVC 3, WebForms, ...  -- what version of Visual Studio are you using?  vs2012 (ultimate, professional, express), vs2010, vs2008 ... -- are you hosting your own website?  are you using a shared hosting service? -- are you experience difficulties in just one browser? more than one browser? -- what browser version(s) are you using?   ie8? ie9? ... -- what is your operating system?     win8, win7, vista, XP, server 2008 R2 ... -- what is your database?   SQL Server 2008 R2, ss2005, MySQL, Oracle, ... -- what is your web server?  iis 7.5, iis 6, .... -- have you provided enough information for someone to be able to answer your question? Here's an actual example from an O.P. that i hope is self-explanatory: I'm trying to make a simple calculator when i write the code in windows application it worked when i tried it in web application it doesn't work and there are no errors what should i do ??!! -- have you included unnecessary information? more than once, i've seen the O.P. (original post, original poster) include many extra lines of code that were not relevant to the actual question; the more unnecessary code that you include, the less likely your volunteer peers will be motivated to donate their time to help you. -- have you asked the question that you want answered? "Does this dog bite?" -- are your expectations reasonable? -- generally, persons who are going to answer your questions are your peers ... they are unpaid volunteers ... -- are you looking for help with your homework, work assignment, or hobby? or, are you expecting someone else to do your work for you?  -- do you expect a complete solution or are you simply looking for guidance and direction? -- you are likely to get more help by first making a reasonable effort to help yourself first Clarity is important, both in question and in answer. if you are answering someone else's question, please remember that clear answers are just as important as clear questions; would you understand your own answer? Things to consider when answering: -- have you tested your code example?  if you have, say so; if you've not tested your code example, also say so -- imho, it's okay to guess as long as you clearly state that you're guessing ... sometimes a wrong guess can still help the O.P. find her/his way to the right answer -- meanness does not contribute to being helpful; sometimes one may become frustrated with the O.P. and/or others participating in a thread, if that happens to you, be kind regardless; speaking from my own experience, at least once i've allowed myself to be frustrated into writing something inappropriate that i've regretted later ... being a meany does not feel good ... being kind and helpful feels fantastic! Tip:  before asking your question, read more than a few existing questions and answers to get a sense of how your peers ask and answer questions. Gerry P.S.:  try to avoid necroposting and piggy backing. necroposting is adding to an old post, especially one that was resolved months ago. piggy backing is adding your own question to someone else's thread.

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  • Creating a Training Lab on Windows Azure

    - by Michael Stephenson
    Originally posted on: http://geekswithblogs.net/michaelstephenson/archive/2013/06/17/153149.aspxThis week we are preparing for a training course that Alan Smith will be running for the support teams at one of my customers around Windows Azure. In order to facilitate the training lab we have a few prerequisites we need to handle. One of the biggest ones is that although the support team all have MSDN accounts the local desktops they work on are not ideal for running most of the labs as we want to give them some additional developer background training around Azure. Some recent Azure announcements really help us in this area: MSDN software can now be used on Azure VM You don't pay for Azure VM's when they are no longer used  Since the support team only have limited experience of Windows Azure and the organisation also have an Enterprise Agreement we decided it would be best value for money to spin up a training lab in a subscription on the EA and then we can turn the machines off when we are done. At the same time we would be able to spin them back up when the users need to do some additional lab work once the training course is completed. In order to achieve this I wanted to create a powershell script which would setup my training lab. The aim was to create 18 VM's which would be based on a prebuilt template with Visual Studio and the Azure development tools. The script I used is described below The Start & Variables The below text will setup the powershell environment and some variables which I will use elsewhere in the script. It will also import the Azure Powershell cmdlets. You can see below that I will need to download my publisher settings file and know some details from my Azure account. At this point I will assume you have a basic understanding of Azure & Powershell so already know how to do this. Set-ExecutionPolicy Unrestrictedcls $startTime = get-dateImport-Module "C:\Program Files (x86)\Microsoft SDKs\Windows Azure\PowerShell\Azure\Azure.psd1"# Azure Publisher Settings $azurePublisherSettings = '<Your settings file>.publishsettings'  # Subscription Details $subscriptionName = "<Your subscription name>" $defaultStorageAccount = "<Your default storage account>"  # Affinity Group Details $affinityGroup = '<Your affinity group>' $dataCenter = 'West Europe' # From Get-AzureLocation  # VM Details $baseVMName = 'TRN' $adminUserName = '<Your admin username>' $password = '<Your admin password>' $size = 'Medium' $vmTemplate = '<The name of your VM template image>' $rdpFilePath = '<File path to save RDP files to>' $machineSettingsPath = '<File path to save machine info to>'    Functions In the next section of the script I have some functions which are used to perform certain actions. The first is called CreateVM. This will do the following actions: If the VM already exists it will be deleted Create the cloud service Create the VM from the template I have created Add an endpoint so we can RDP to them all over the same port Download the RDP file so there is a short cut the trainees can easily access the machine via Write settings for the machine to a log file  function CreateVM($machineNo) { # Specify a name for the new VM $machineName = "$baseVMName-$machineNo" Write-Host "Creating VM: $machineName"       # Get the Azure VM Image      $myImage = Get-AzureVMImage $vmTemplate   #If the VM already exists delete and re-create it $existingVm = Get-AzureVM -Name $machineName -ServiceName $serviceName if($existingVm -ne $null) { Write-Host "VM already exists so deleting it" Remove-AzureVM -Name $machineName -ServiceName $serviceName }   "Creating Service" $serviceName = "bupa-azure-train-$machineName" Remove-AzureService -Force -ServiceName $serviceName New-AzureService -Location $dataCenter -ServiceName $serviceName   Write-Host "Creating VM: $machineName" New-AzureQuickVM -Windows -name $machineName -ServiceName $serviceName -ImageName $myImage.ImageName -InstanceSize $size -AdminUsername $adminUserName -Password $password  Write-Host "Updating the RDP endpoint for $machineName" Get-AzureVM -name $machineName -ServiceName $serviceName ` | Add-AzureEndpoint -Name RDP -Protocol TCP -LocalPort 3389 -PublicPort 550 ` | Update-AzureVM    Write-Host "Get the RDP File for machine $machineName" $machineRDPFilePath = "$rdpFilePath\$machineName.rdp" Get-AzureRemoteDesktopFile -name $machineName -ServiceName $serviceName -LocalPath "$machineRDPFilePath"   WriteMachineSettings "$machineName" "$serviceName" }    The delete machine settings function is used to delete the log file before we start re-running the process.  function DeleteMachineSettings() { Write-Host "Deleting the machine settings output file" [System.IO.File]::Delete("$machineSettingsPath"); }    The write machine settings function will get the VM and then record its details to the log file. The importance of the log file is that I can easily provide the information for all of the VM's to our infrastructure team to be able to configure access to all of the VM's    function WriteMachineSettings([string]$vmName, [string]$vmServiceName) { Write-Host "Writing to the machine settings output file"   $vm = Get-AzureVM -name $vmName -ServiceName $vmServiceName $vmEndpoint = Get-AzureEndpoint -VM $vm -Name RDP   $sb = new-object System.Text.StringBuilder $sb.Append("Service Name: "); $sb.Append($vm.ServiceName); $sb.Append(", "); $sb.Append("VM: "); $sb.Append($vm.Name); $sb.Append(", "); $sb.Append("RDP Public Port: "); $sb.Append($vmEndpoint.Port); $sb.Append(", "); $sb.Append("Public DNS: "); $sb.Append($vmEndpoint.Vip); $sb.AppendLine(""); [System.IO.File]::AppendAllText($machineSettingsPath, $sb.ToString());  } # end functions    Rest of Script In the rest of the script it is really just the bit that orchestrates the actions we want to happen. It will load the publisher settings, select the Azure subscription and then loop around the CreateVM function and create 16 VM's  Import-AzurePublishSettingsFile $azurePublisherSettings Set-AzureSubscription -SubscriptionName $subscriptionName -CurrentStorageAccount $defaultStorageAccount Select-AzureSubscription -SubscriptionName $subscriptionName  DeleteMachineSettings    "Starting creating Bupa International Azure Training Lab" $numberOfVMs = 16  for ($index=1; $index -le $numberOfVMs; $index++) { $vmNo = "$index" CreateVM($vmNo); }    "Finished creating Bupa International Azure Training Lab" # Give it a Minute Start-Sleep -s 60  $endTime = get-date "Script run time " + ($endTime - $startTime)    Conclusion As you can see there is nothing too fancy about this script but in our case of creating a small isolated training lab which is not connected to our corporate network then we can easily use this to provision the lab. Im sure if this is of use to anyone you can easily modify it to do other things with the lab environment too. A couple of points to note are that there are some soft limits in Azure about the number of cores and services your subscription can use. You may need to contact the Azure support team to be able to increase this limit. In terms of the real business value of this approach, it was not possible to use the existing desktops to do the training on, and getting some internal virtual machines would have been relatively expensive and time consuming for our ops team to do. With the Azure option we are able to spin these machines up for a temporary period during the training course and then throw them away when we are done. We expect the costing of this test lab to be very small, especially considering we have EA pricing. As a ball park I think my 18 lab VM training environment will cost in the region of $80 per day on our EA. This is a fraction of the cost of the creation of a single VM on premise.

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  • Agile Like Jazz

    - by Jeff Certain
    (I’ve been sitting on this for a week or so now, thinking that it needed to be tightened up a bit to make it less rambling. Since that’s clearly not going to happen, reader beware!) I had the privilege of spending around 90 minutes last night sitting and listening to Sonny Rollins play a concert at the Disney Center in LA. If you don’t know who Sonny Rollins is, I don’t know how to explain the experience; if you know who he is, I don’t need to. Suffice it to say that he has been recording professionally for over 50 years, and helped create an entire genre of music. A true master by any definition. One of the most intriguing aspects of a concert like this, however, is watching the master step aside and let the rest of the musicians play. Not just play their parts, but really play… letting them take over the spotlight, to strut their stuff, to soak up enthusiastic applause from the crowd. Maybe a lot of it has to do with the fact that Sonny Rollins has been doing this for more than a half-century. Maybe it has something to do with a kind of patience you learn when you’re on the far side of 80 – and the man can still blow a mean sax for 90 minutes without stopping! Maybe it has to do with the fact that he was out there for the love of the music and the love of the show, not because he had anything to prove to anyone and, I like to think, not for the money. Perhaps it had more to do with the fact that, when you’re at that level of mastery, the other musicians are going to be good. Really good. Whatever the reasons, there was a incredible freedom on that stage – the ability to improvise, for each musician to showcase their own specialization and skills, and them come back to the common theme, back to being on the same page, as it were. All this took place in the same venue that is home to the L.A. Phil. Somehow, I can’t ever see the same kind of free-wheeling improvisation happening in that context. And, since I’m a geek, I started thinking about agility. Rollins has put together a quintet that reflects his own particular style and past. No upright bass or piano for Rollins – drums, bongos, electric guitar and bass guitar along with his sax. It’s not about the mix of instruments. Other trios, quartets, and sextets use different mixes of instruments. New Orleans jazz tends towards trombones instead of sax; some prefer cornet or trumpet. But no matter what the choice of instruments, size matters. Team sizes are something I’ve been thinking about for a while. We’re on a quest to rethink how our teams are organized. They just feel too big, too unwieldy. In fact, they really don’t feel like teams at all. Most of the time, they feel more like collections or people who happen to report to the same manager. I attribute this to a couple factors. One is over-specialization; we have a tendency to have people work in silos. Although the teams are product-focused, within them our developers are both generalists and specialists. On the one hand, we expect them to be able to build an entire vertical slice of the application; on the other hand, each developer tends to be responsible for the vertical slice. As a result, developers often work on their own piece of the puzzle, in isolation. This sort of feels like working on a jigsaw in a group – each person taking a set of colors and piecing them together to reveal a portion of the overall picture. But what inevitably happens when you go to meld all those pieces together? Inevitably, you have some sections that are too big to move easily. These sections end up falling apart under their own weight as you try to move them. Not only that, but there are other challenges – figuring out where that section fits, and how to tie it into the rest of the puzzle. Often, this is when you find a few pieces need to be added – these pieces are “glue,” if you will. The other issue that arises is due to the overhead of maintaining communications in a team. My mother, who worked in IT for around 30 years, once told me that 20% per team member is a good rule of thumb for maintaining communication. While this is a rule of thumb, it seems to imply that any team over about 6 people is going to become less agile simple because of the communications burden. Teams of ten or twelve seem like they fall into the philharmonic organizational model. Complicated pieces of music requiring dozens of players to all be on the same page requires a much different model than the jazz quintet. There’s much less room for improvisation, originality or freedom. (There are probably orchestral musicians who will take exception to this characterization; I’m calling it like I see it from the cheap seats.) And, there’s one guy up front who is running the show, whose job is to keep all of those dozens of players on the same page, to facilitate communications. Somehow, the orchestral model doesn’t feel much like a self-organizing team, either. The first violin may be the best violinist in the orchestra, but they don’t get to perform free-wheeling solos. I’ve never heard of an orchestra getting together for a jam session. But I have heard of teams that organize their work based on the developers available, rather than organizing the developers based on the work required. I have heard of teams where desired functionality is deferred – or worse yet, schedules are missed – because one critical person doesn’t have any bandwidth available. I’ve heard of teams where people simply don’t have the big picture, because there is too much communication overhead for everyone to be aware of everything that is happening on a project. I once heard Paul Rayner say something to the effect of “you have a process that is perfectly designed to give you exactly the results you have.” Given a choice, I want a process that’s much more like jazz than orchestral music. I want a process that doesn’t burden me with lots of forms and checkboxes and stuff. Give me the simplest, most lightweight process that will work – and a smaller team of the best developers I can find. This seems like the kind of process that will get the kind of result I want to be part of.

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  • PASS: Election Changes for 2011

    - by Bill Graziano
    Last year after the election, the PASS Board created an Election Review Committee.  This group was charged with reviewing our election procedures and making suggestions to improve the process.  You can read about the formation of the group and review some of the intermediate work on the site – especially in the forums. I was one of the members of the group along with Joe Webb (Chair), Lori Edwards, Brian Kelley, Wendy Pastrick, Andy Warren and Allen White.  This group worked from October to April on our election process.  Along the way we: Interviewed interested parties including former NomCom members, Board candidates and anyone else that came forward. Held a session at the Summit to allow interested parties to discuss the issues Had numerous conference calls and worked through the various topics I can’t thank these people enough for the work they did.  They invested a tremendous number of hours thinking, talking and writing about our elections.  I’m proud to say I was a member of this group and thoroughly enjoyed working with everyone (even if I did finally get tired of all the calls.) The ERC delivered their recommendations to the PASS Board prior to our May Board meeting.  We reviewed those and made a few modifications.  I took their recommendations and rewrote them as procedures while incorporating those changes.  Their original recommendations as well as our final document are posted at the ERC documents page.  Please take a second and read them BEFORE we start the elections.  If you have any questions please post them in the forums on the ERC site. (My final document includes a change log at the end that I decided to leave in.  If you want to know which areas to pay special attention to that’s a good start.) Many of those recommendations were already posted in the forums or in the blogs of individual ERC members.  Hopefully nothing in the ERC document is too surprising. In this post I’m going to walk through some of the key changes and talk about what I remember from both ERC and Board discussions.  I’ll pay a little extra attention to things the Board changed from the ERC.  I’d also encourage any of the Board or ERC members to blog their thoughts on this. The Nominating Committee will continue to exist.  Personally, I was curious to see what the non-Board ERC members would think about the NomCom.  There was broad agreement that a group to vet candidates had value to the organization. The NomCom will be composed of five members.  Two will be Board members and three will be from the membership at large.  The only requirement for the three community members is that you’ve volunteered in some way (and volunteering is defined very broadly).  We expect potential at-large NomCom members to participate in a forum on the PASS site to answer questions from the other PASS members. We’re going to hold an election to determine the three community members.  It will be closer to voting for Summit sessions than voting for Board members.  That means there won’t be multiple dedicated emails.  If you’re at all paying attention it will be easy to participate.  Personally I wanted it easy for those that cared to participate but not overwhelm those that didn’t care.  I think this strikes a good balance. There’s also a clause that in order to be considered a winner in this NomCom election, you must receive 10 votes.  This is something I suggested.  I have no idea how popular the NomCom election is going to be.  I just wanted a fallback that if no one participated and some random person got in with one or two votes.  Any open slots will be filled by the NomCom chair (usually the PASS Immediate Past President).  My assumption is that they would probably take the next highest vote getters unless they were throwing flames in the forums or clearly unqualified.  As a final check, the Board still approves the final NomCom. The NomCom is going to rank candidates instead of rating them.  This has interesting implications.  This was championed by another ERC member and I’m hoping they write something about it.  This will really force the NomCom to make decisions between candidates.  You can’t just rate everyone a 3 and be done with it.  It may also make candidates appear further apart than they actually are.  I’m looking forward talking with the NomCom after this election and getting their feedback on this. The PASS Board added an option to remove a candidate with a unanimous vote of the NomCom.  This was primarily put in place to handle people that lied on their application or had a criminal background or some other unusual situation and we figured it out. We list an explicit goal of three candidate per open slot. We also wanted an easy way to find the NomCom candidate rankings from the ballot.  Hopefully this will satisfy those that want a broad candidate pool and those that want the NomCom to identify the most qualified candidates. The primary spokesperson for the NomCom is the committee chair.  After the issues around the election last year we didn’t have a good communication plan in place.  We should have and that was a failure on the part of the Board.  If there is criticism of the election this year I hope that falls squarely on the Board.  The community members of the NomCom shouldn’t be fielding complaints over the election process.  That said, the NomCom is ranking candidates and we are forcing them to rank some lower than others.  I’m sure you’ll each find someone that you think should have been ranked differently.  I also want to highlight one other change to the process that we started last year and isn’t included in these documents.  I think the candidate forums on the PASS site were tremendously helpful last year in helping people to find out more about candidates.  That gives our members a way to ask hard questions of the candidates and publicly see their answers. This year we have two important groups to fill.  The first is the NomCom.  We need three people from our membership to step up and fill this role.  It won’t be easy.  You will have to make subjective rankings of your fellow community members.  Your actions will be important in deciding who the future leaders of PASS will be.  There’s a 50/50 chance that one of the people you interview will be the President of PASS someday.  This is not a responsibility to be taken lightly. The second is the slate of candidates.  If you’ve ever thought about running for the Board this is the year.  We’ve never had nine candidates on the ballot before.  Your chance of making it through the NomCom are higher than in any previous year.  Unfortunately the more of you that run, the more of you that will lose in the election.  And hopefully that competition will mean more community involvement and better Board members for PASS. Is this the end of changes to the election process?  It isn’t.  Every year that I’ve been on the Board the election process has changed.  Some years there have been small changes and some years there have been large changes.  After this election we’ll look at how the process worked and decide what steps to take – just like we do every year.

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  • Mobile BI Comes of Age

    - by rich.clayton(at)oracle.com
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} One of the hot topics in the Business Intelligence industry is mobility.  More specifically the question is how business can be transformed by the iPhone and the iPad.  In June 2003, Gartner predicted that Mobile BI would be obsolete and that the technology was headed for the 'trough of disillusionment'.  I agreed with them at that time.  Many vendors like MicroStrategy and Business Objects jumped into the fray attempting to show how PDA's like Palm Pilots could be integrated with BI.  Their investments resulted in interesting demos with no commercial traction.  Why, because wireless networks and mobile operating systems were primitive, immature and slow. In my opinion, Apple's iOS has changed everything in Mobile BI.  Yes Blackberry, Android and Symbian and all the rest have their place in the market but I believe that increasingly consumers (not IT departments) influence BI decision making processes.  Consumers are choosing the iPhone and the iPad. The number of iPads I see in business meetings now is staggering.  Some use it for email and note taking and others are starting to use corporate applications.  The possibilities for Mobile BI are countless and I would expect to see iPads enterprise-wide over the next few years.   These new devices will provide just-in-time access to critical business information.  Front-line managers interacting with customers, suppliers, patients or citizens will have information literally at their fingertips. I've experimented with several mobile BI tools.  They look cool but like their Executive Information System (EIS) predecessors of the 1990's these tools lack a backbone and a plausible integration strategy.  EIS was a viral technology in the early 1990's.  Executives from every industry and job function were showcasing their dashboards to fellow co-workers and colleagues at the country club.  Just like the iPad, every senior manager wanted one.  EIS wasn't a device however, it was a software application.   EIS quickly faded into the software sunset as it lacked integration with corporate information systems.  BI servers  replaced EIS because the technology focused on the heavy data lifting of integrating, normalizing, aggregating and managing large, complex data volumes.  The devices are here to stay. The cute stand-alone mobile BI tools, not so much. If all you're looking to do is put Excel files on your iPad, there are plenty of free tools on the market.  You'll look cool at your next management meeting but after a few weeks, the cool factor will fade away and you'll be wondering how you will ever maintain it.  If however you want secure, consistent, reliable information on your iPad, you need an integration strategy and a way to model the data.  BI Server technologies like the Oracle BI Foundation is a market leading approach to tackle that issue. I liken the BI mobility frenzy to buying classic cars.  Classic Cars have two buying groups - teenagers and middle-age folks looking to tinker.  Teenagers look at the pin-stripes and the paint job while middle-agers (like me)  kick the tires a bit and look under the hood to check out the quality and reliability of the engine.  Mobile BI tools sure look sexy but don't go very far without an engine and a transmission or an integration strategy. The strategic question in Mobile BI is can these startups build a motor and transmission faster than Oracle can re-paint the car?  Oracle has a great engine and a transmission that connects to all enterprise information assets.  We're working on the new paint job and are excited about the possibilities.  Just as vertical integration worked in the automotive business, it too works in the technology industry.

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 2 – Table per Type (TPT)

    - by mortezam
    In the previous blog post you saw that there are three different approaches to representing an inheritance hierarchy and I explained Table per Hierarchy (TPH) as the default mapping strategy in EF Code First. We argued that the disadvantages of TPH may be too serious for our design since it results in denormalized schemas that can become a major burden in the long run. In today’s blog post we are going to learn about Table per Type (TPT) as another inheritance mapping strategy and we'll see that TPT doesn’t expose us to this problem. Table per Type (TPT)Table per Type is about representing inheritance relationships as relational foreign key associations. Every class/subclass that declares persistent properties—including abstract classes—has its own table. The table for subclasses contains columns only for each noninherited property (each property declared by the subclass itself) along with a primary key that is also a foreign key of the base class table. This approach is shown in the following figure: For example, if an instance of the CreditCard subclass is made persistent, the values of properties declared by the BillingDetail base class are persisted to a new row of the BillingDetails table. Only the values of properties declared by the subclass (i.e. CreditCard) are persisted to a new row of the CreditCards table. The two rows are linked together by their shared primary key value. Later, the subclass instance may be retrieved from the database by joining the subclass table with the base class table. TPT Advantages The primary advantage of this strategy is that the SQL schema is normalized. In addition, schema evolution is straightforward (modifying the base class or adding a new subclass is just a matter of modify/add one table). Integrity constraint definition are also straightforward (note how CardType in CreditCards table is now a non-nullable column). Another much more important advantage is the ability to handle polymorphic associations (a polymorphic association is an association to a base class, hence to all classes in the hierarchy with dynamic resolution of the concrete class at runtime). A polymorphic association to a particular subclass may be represented as a foreign key referencing the table of that particular subclass. Implement TPT in EF Code First We can create a TPT mapping simply by placing Table attribute on the subclasses to specify the mapped table name (Table attribute is a new data annotation and has been added to System.ComponentModel.DataAnnotations namespace in CTP5): public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } [Table("BankAccounts")] public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } } [Table("CreditCards")] public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; } } If you prefer fluent API, then you can create a TPT mapping by using ToTable() method: protected override void OnModelCreating(ModelBuilder modelBuilder) {     modelBuilder.Entity<BankAccount>().ToTable("BankAccounts");     modelBuilder.Entity<CreditCard>().ToTable("CreditCards"); } Generated SQL For QueriesLet’s take an example of a simple non-polymorphic query that returns a list of all the BankAccounts: var query = from b in context.BillingDetails.OfType<BankAccount>() select b; Executing this query (by invoking ToList() method) results in the following SQL statements being sent to the database (on the bottom, you can also see the result of executing the generated query in SQL Server Management Studio): Now, let’s take an example of a very simple polymorphic query that requests all the BillingDetails which includes both BankAccount and CreditCard types: projects some properties out of the base class BillingDetail, without querying for anything from any of the subclasses: var query = from b in context.BillingDetails             select new { b.BillingDetailId, b.Number, b.Owner }; -- var query = from b in context.BillingDetails select b; This LINQ query seems even more simple than the previous one but the resulting SQL query is not as simple as you might expect: -- As you can see, EF Code First relies on an INNER JOIN to detect the existence (or absence) of rows in the subclass tables CreditCards and BankAccounts so it can determine the concrete subclass for a particular row of the BillingDetails table. Also the SQL CASE statements that you see in the beginning of the query is just to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type) TPT ConsiderationsEven though this mapping strategy is deceptively simple, the experience shows that performance can be unacceptable for complex class hierarchies because queries always require a join across many tables. In addition, this mapping strategy is more difficult to implement by hand— even ad-hoc reporting is more complex. This is an important consideration if you plan to use handwritten SQL in your application (For ad hoc reporting, database views provide a way to offset the complexity of the TPT strategy. A view may be used to transform the table-per-type model into the much simpler table-per-hierarchy model.) SummaryIn this post we learned about Table per Type as the second inheritance mapping in our series. So far, the strategies we’ve discussed require extra consideration with regard to the SQL schema (e.g. in TPT, foreign keys are needed). This situation changes with the Table per Concrete Type (TPC) that we will discuss in the next post. References ADO.NET team blog Java Persistence with Hibernate book a { text-decoration: none; } a:visited { color: Blue; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } p.MsoNormal { margin-top: 0in; margin-right: 0in; margin-bottom: 10.0pt; margin-left: 0in; line-height: 115%; font-size: 11.0pt; font-family: "Calibri" , "sans-serif"; }

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  • Securing an ADF Application using OES11g: Part 1

    - by user12587121
    Future releases of the Oracle stack should allow ADF applications to be secured natively with Oracle Entitlements Server (OES). In a sequence of postings here I explore one way to achive this with the current technology, namely OES 11.1.1.5 and ADF 11.1.1.6. ADF Security Basics ADF Bascis The Application Development Framework (ADF) is Oracle’s preferred technology for developing GUI based Java applications.  It can be used to develop a UI for Swing applications or, more typically in the Oracle stack, for Web and J2EE applications.  ADF is based on and extends the Java Server Faces (JSF) technology.  To get an idea, Oracle provides an online demo to showcase ADF components. ADF can be used to develop just the UI part of an application, where, for example, the data access layer is implemented using some custom Java beans or EJBs.  However ADF also has it’s own data access layer, ADF Business Components (ADF BC) that will allow rapid integration of data from data bases and Webservice interfaces to the ADF UI component.   In this way ADF helps implement the MVC  approach to building applications with UI and data components. The canonical tutorial for ADF is to open JDeveloper, define a connection to a database, drag and drop a table from the database view to a UI page, build and deploy.  One has an application up and running very quickly with the ability to quickly integrate changes to, for example, the DB schema. ADF allows web pages to be created graphically and components like tables, forms, text fields, graphs and so on to be easily added to a page.  On top of JSF Oracle have added drag and drop tooling with JDeveloper and declarative binding of the UI to the data layer, be it database, WebService or Java beans.  An important addition is the bounded task flow which is a reusable set of pages and transitions.   ADF adds some steps to the page lifecycle defined in JSF and adds extra widgets including powerful visualizations. It is worth pointing out that the Oracle Web Center product (portal, content management and so on) is based on and extends ADF. ADF Security ADF comes with it’s own security mechanism that is exposed by JDeveloper at development time and in the WLS Console and Enterprise Manager (EM) at run time. The security elements that need to be addressed in an ADF application are: authentication, authorization of access to web pages, task-flows, components within the pages and data being returned from the model layer. One  typically relies on WLS to handle authentication and because of this users and groups will also be handled by WLS.  Typically in a Dev environment, users and groups are stored in the WLS embedded LDAP server. One has a choice when enabling ADF security (Application->Secure->Configure ADF Security) about whether to turn on ADF authorization checking or not: In the case where authorization is enabled for ADF one defines a set of roles in which we place users and then we grant access to these roles to the different ADF elements (pages or task flows or elements in a page). An important notion here is the difference between Enterprise Roles and Application Roles. The idea behind an enterprise role is that is defined in terms of users and LDAP groups from the WLS identity store.  “Enterprise” in the sense that these are things available for use to all applications that use that store.  The other kind of role is an Application Role and the idea is that  a given application will make use of Enterprise roles and users to build up a set of roles for it’s own use.  These application roles will be available only to that application.   The general idea here is that the enterprise roles are relatively static (for example an Employees group in the LDAP directory) while application roles are more dynamic, possibly depending on time, location, accessed resource and so on.  One of the things that OES adds that is that we can define these dynamic membership conditions in Role Mapping Policies. To make this concrete, here is how, at design time in Jdeveloper, one assigns these rights in Jdeveloper, which puts them into a file called jazn-data.xml: When the ADF app is deployed to a WLS this JAZN security data is pushed to the system-jazn-data.xml file of the WLS deployment for the policies and application roles and to the WLS backing LDAP for the users and enterprise roles.  Note the difference here: after deploying the application we will see the users and enterprise roles show up in the WLS LDAP server.  But the policies and application roles are defined in the system-jazn-data.xml file.  Consult the embedded WLS LDAP server to manage users and enterprise roles by going to the domain console and then Security Realms->myrealm->Users and Groups: For production environments (or in future to share this data with OES) one would then perform the operation of “reassociating” this security policy and application role data to a DB schema (or an LDAP).  This is done in the EM console by reassociating the Security Provider.  This blog posting has more explanations and references on this reassociation process. If ADF Authentication and Authorization are enabled then the Security Policies for a deployed application can be managed in EM.  Our goal is to be able to manage security policies for the applicaiton rather via OES and it's console. Security Requirements for an ADF Application With this package tour of ADF security we can see that to secure an ADF application with we would expect to be able to take care of at least the following items: Authentication, including a user and user-group store Authorization for page access Authorization for bounded Task Flow access.  A bounded task flow has only one point of entry and so if we protect that entry point by calling to OES then all the pages in the flow are protected.  Authorization for viewing data coming from the data access layer In the next posting we will describe a sample ADF application and required security policies. References ADF Dev Guide: Fusion Middleware Fusion Developer's Guide for Oracle Application Development Framework: Enabling ADF Security in a Fusion Web Application Oracle tutorial on securing a sample ADF application, appears to require ADF 11.1.2 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Why We Should Learn to Stop Worrying and Love Millennials

    - by HCM-Oracle
    By Christine Mellon Much is said and written about the new generations of employees entering our workforce, as though they are a strange specimen, a mysterious life form to be “figured out,” accommodated and engaged – at a safe distance, of course.  At its worst, this talk takes a critical and disapproving tone, with baby boomer employees adamantly refusing to validate this new breed of worker, let alone determine how to help them succeed and achieve their potential.   The irony of our baby-boomer resentments and suspicions is that they belie the fact that we created the very vision that younger employees are striving to achieve.  From our frustrations with empty careers that did not fulfill us, from our opposition to “the man,” from our sharp memories of our parents’ toiling for 30 years just for the right to retire, from the simple desire not to live our lives in a state of invisibility, came the seeds of hope for something better. One characteristic of Millennial workers that grew from these seeds is the desire to experience as much as possible.  They are the “Experiential Employee”, with a passion for growing in diverse ways and expanding personal and professional horizons.  Rather than rooting themselves in a single company for a career, or even in a single career path, these employees are committed to building a broad portfolio of experiences and capabilities that will enable them to make a difference and to leave a mark of significance in the world.  How much richer is the organization that nurtures and leverages this inclination?  Our curmudgeonly ways must be surrendered and our focus redirected toward building the next generation of talent ecosystems, if we are to optimize what future generations have to offer.   Accelerating Professional Development In spite of our Boomer grumblings about Millennials’ “unrealistic” expectations, the truth is that we have a well-matched set of circumstances.  We have executives-in-waiting who want to learn quickly and a concurrent, urgent need to ramp up their development time, based on anticipated high levels of retirement in the next 10+ years.  Since we need to rapidly skill up these heirs to the corporate kingdom, isn’t it a fortunate coincidence that they are hungry to learn, develop and move fluidly throughout our organizations??  So our challenge now is to efficiently operationalize the wisdom we have acquired about effective learning and development.   We have already evolved from classroom-based models to diverse instructional methods.  The next step is to find the best approaches to help younger employees learn quickly and apply new learnings in an impactful way.   Creating temporary or even permanent functional partnerships among Millennial employees is one way to maximize outcomes.  This might take the form of 2 or more employees owning aspects of what once fell under a single role.  While one might argue this would mean duplication of resources, it could be a short term cost while employees come up to speed.  And the potential benefits would be numerous:  leveraging and validating the inherent sense of community of new generations, creating cross-functional skills with broad applicability, yielding additional perspectives and approaches to traditional work outcomes, and accelerating the performance curve for incumbents through Cooperative Learning (Johnson, D. and Johnson R., 1989, 1999).  This well-researched teaching strategy, where students support each other in the absorption and application of new information, has been shown to deliver faster, more efficient learning, and greater retention. Alternately, perhaps short term contracts with exiting retirees, or former retirees, to help facilitate the development of following generations may have merit.  Again, a short term cost, certainly.  However, the gains realized in shortening the learning curve, and strengthening engagement are substantial and lasting. Ultimately, there needs to be creative thinking applied for each organization on how to accelerate the capabilities of our future leaders in unique ways that mesh with current culture. The manner in which performance is evaluated must finally shift as well.  Employees will need to be assessed on how well they have developed key skills and capabilities vs. end-to-end mastery of functional positions they have no interest in keeping for an entire career. As we become more comfortable in placing greater and greater weight on competencies vs. tasks, we will realize increased organizational agility via this new generation of workers, which will be further enhanced by their natural flexibility and appetite for change. Revisiting Succession  For many years, organizations have failed to deliver desired succession planning outcomes.  According to CEB’s 2013 research, only 28% of current leaders were pre-identified in a succession plan. These disappointing results, along with the entrance of the experiential, Millennial employee into the workforce, may just provide the needed impetus for HR to reinvent succession processes.   We have recognized that the best professional development efforts are not always linear, and the time has come to fully adopt this philosophy in regard to succession as well.  Paths to specific organizational roles will not look the same for newer generations who seek out unique learning opportunities, without consideration of a singular career destination.  Rather than charting particular jobs as precursors for key positions, the experiences and skills behind what makes an incumbent successful must become essential in succession mapping.  And the multitude of ways in which those experiences and skills may be acquired must be factored into the process, along with the individual employee’s level of learning agility. While this may seem daunting, it is necessary and long overdue.  We have talked about the criticality of competency-based succession, however, we have not lived up to our own rhetoric.  Many Boomers have experienced the same frustration in our careers; knowing we are capable of shining in a particular role, but being denied the opportunity due to how our career history lined up, on paper, with documented job requirements.  These requirements usually emphasized past jobs/titles and specific tasks, versus capabilities, drive and willingness (let alone determination) to learn new things.  How satisfying would it be for us to leave a legacy where such narrow thinking no longer applies and potential is amplified? Realizing Diversity Another bloom from the seeds we Boomers have tried to plant over the past decades is a completely evolved view of diversity.  Millennial employees assume a diverse workforce, and are startled by anything less.  Their social tolerance, nurtured by wide and diverse networks, is unprecedented.  College graduates expect a similar landscape in the “real world” to what they experienced throughout their lives.  They appreciate and seek out divergent points of view and experiences without needing any persuasion.  The face of our U.S. workforce will likely see dramatic change as Millennials apply their fresh take on hiring and building strong teams, with an inherent sense of inclusion.  This wonderful aspect of the Millennial wave should be celebrated and strongly encouraged, as it is the fulfillment of our own aspirations. Future Perfect The Experiential Employee is operating more as a free agent than a long term player, and their commitment will essentially last as long as meaningful organizational culture and personal/professional opportunities keep their interest.  As Boomers, we have laid the foundation for this new, spirited employment attitude, and we should take pride in knowing that.  Generations to come will challenge organizations to excel in how they identify, manage and nurture talent. Let’s support and revel in the future that we’ve helped invent, rather than lament what we think has been lost.  After all, the future is always connected to the past.  And as so eloquently phrased by Antoine Lavoisier, French nobleman, chemist and politico:  “Nothing is Lost, Nothing is Created, and Everything is Transformed.” Christine has over 25 years of diverse HR experience.  She has held HR consulting and corporate roles, including CHRO positions for Echostar in Denver, a 6,000+ employee global engineering firm, and Aepona, a startup software firm, successfully acquired by Intel. Christine is a resource to Oracle clients, to assist in Human Capital Management strategy development and implementation, compensation practices, talent development initiatives, employee engagement, global HR management, and integrated HR systems and processes that support the full employee lifecycle. 

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  • BRE (Business Rules Engine) Data Services is out...!!!

    - by Vishal
    A few months ago we at Tellago had open sourced the BizTalk Data Services. We were meanwhile working on other artifacts which comes along with BizTalk Server like the “Business Rules Engine”.  We are happy to announce the first version of BRE Data Services. BRE Data Services is a same concept which we covered through BTS Data Services, providing a RESTFul OData – based API to interact with the Business Rules Engine via HTTP using ATOM Publishing Protocol or JSON as the encoding mechanism.   In the first version release, we mainly focused on the browsing, querying and searching BRE artifacts via a RESTFul interface. Also along with that we provide the functionality to execute Business Rules by inserting the Facts for policies via the IUpdatable implementation of WCF Data Services.   The BRE Data Services API provides a lightweight interface for managing Business Rules Engine artifacts such as Policies, Rules, Vocabularies, Conditions, Actions, Facts etc. The following are some examples which details some of the available features in the current version of the API.   Basic Querying: Querying BRE Policies http://localhost/BREDataServices/BREMananagementService.svc/Policies Querying BRE Rules http://localhost/BREDataServices/BREMananagementService.svc/Rules Querying BRE Vocabularies http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies   Navigation: The BRE Data Services API also leverages WCF Data Services to enable navigation across related different BRE objects. Querying a specific Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies(‘PolicyName’) Querying a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules(‘RuleName’) Querying all Rules under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Rules Querying all Facts under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Facts Querying all Actions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying all Conditions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying a specific Vocabulary: http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies('VocabName')   Implementation: With the BRE Data Services, we also provide the functionality of executing a particular policy via HTTP. There are couple of ways you can do that though the API.   Ø First is though Service Operations feature of WCF Data Services in which you can execute the Facts by passing them in the URL itself. This is a very simple implementations of the executing the policies due to the limitations & restrictions (only primitive types of input parameters which can be passed) currently of the Service Operations of the WCF Data Services. Below is a code sample.                Below is a traced Request/Response message.                                 Ø Second is through the IUpdatable Interface of WCF Data Services. In this method, you can first query the rule which you want to execute and then inserts Facts for that particular Rules and finally when you perform the SaveChanges() call for the IUpdatable Interface API, it executes the policy with the facts which you inserted at runtime. Below is a sample of client side code. Due to the limitations of current version of WCF Data Services where there is no way you can return back the updates happening on the service side back to the client via the SaveChanges() method. Here we are executing the rule passing a serialized XML as Facts and there is no changes made to any data where we can query back to fetch the changes. This is overcome though the first way to executing the policies which is by executing it as a Service Operation call.     This actually generates a AtomPub message shown as below:   POST /Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/$batch HTTP/1.1 User-Agent: Microsoft ADO.NET Data Services DataServiceVersion: 1.0;NetFx MaxDataServiceVersion: 2.0;NetFx Accept: application/atom+xml,application/xml Accept-Charset: UTF-8 Content-Type: multipart/mixed; boundary=batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Host: localhost:8080 Content-Length: 1481 Expect: 100-continue   --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Content-Type: multipart/mixed; boundary=changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf   --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf Content-Type: application/http Content-Transfer-Encoding: binary   MERGE http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy') HTTP/1.1 Content-ID: 4 Content-Type: application/atom+xml;type=entry Content-Length: 927   <?xml version="1.0" encoding="utf-8" standalone="yes"?> <entry xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" font-size: x-small"http://www.w3.org/2005/Atom">   <category scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" term="Tellago.BRE.REST.Resources.Fact" />   <title />   <author>     <name />   </author>   <updated>2011-01-31T20:09:15.0023982Z</updated>   <id>http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy')</id>   <content type="application/xml">     <m:properties>       <d:FactInstance>&lt;ns0:LoanStatus xmlns:ns0="http://tellago.com"&gt;&lt;Age&gt;10&lt;/Age&gt;&lt;Status&gt;true&lt;/Status&gt;&lt;/ns0:LoanStatus&gt;</d:FactInstance>       <d:FactType>TestSchema</d:FactType>       <d:ID>TestPolicy</d:ID>     </m:properties>   </content> </entry> --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf-- --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7—     Installation: The installation of the BRE Data Services is pretty straight forward. ·         Create a new IIS website say BREDataServices. ·         Download the SourceCode from TellagoCodeplex and copy the content from Tellago.BRE.REST.ServiceHost to the physical location of the above created website.     ·         The appPool account running the website should have admin access to the BizTalkRuleEngineDb database. ·         TheRight click the BREManagementService.svc in the IIS ContentView for the website and wala..     Conclusion: The BRE Data Services API is an experiment intended to bring the capabilities of RESTful/OData based services to the Traditional BTS/BRE Solutions. The future releases will target on technologies like BAM, ESB Toolkit. This version has been tested with various version of BizTalk Server and we have uploaded the source code to our Tellago's DevLabs workspace at Codeplex. I hope you guys enjoy this release. Keep an eye on our new releases @ Tellago Codeplex. We are working on various other Biztalk Artifacts like BAM, ESB Toolkit.     Till than happy BizzRuling…!!!     Thanks,   Vishal Mody

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  • SQL Sentry First Impressions

    - by AjarnMark
    After struggling to defend my SQL Servers from a political attack recently, I realized that I needed better tools to back me up, and SQL Sentry is the leading candidate. A couple of weeks ago, seemingly from out of nowhere, complaints from the business users started coming in that one of the core internal applications was running dramatically slower than normal, and fingers were being pointed at the SQL Server.  Unfortunately, we don’t have a production DBA whose entire job is to monitor and maintain our SQL Servers.  The responsibility falls to me to do the best I can, investing only a small portion of my time, because there are so many other responsibilities to take care of, and our industry is still deep in recession.  I inherited these SQL Servers and have made significant improvements in process and procedure, but I had not yet made the time to take real baseline measurements or keep a really close eye on the performance.  Like many DBAs, I wrote several of my own tools and used the “built-in tools” like Profiler, PerfMon, and sp_who2 (did I mention most of our instances are SQL Server 2000?).  These have all served me well for in-the-moment troubleshooting and maintenance, but they really fell down on the job when I was called upon to “prove” that SQL Server performance was acceptable and more importantly had not degraded recently (i.e. historical comparisons).  I really didn’t have anything from a historical comparison perspective, but I was able to show that current performance was acceptable, and deflect attention back onto other components (which in fact turned out to be the real culprit). That experience dramatically illustrated the need for better monitoring tools.  Coincidentally, I had been talking recently to my boss about the mini nightmare of monitoring several critical and interdependent overnight jobs that operate on separate instances of SQL Server.  Among other tools, I had been using Idera’s SQL Job Manager which is a free tool and did a nice job of showing me job schedules and histories in a nice calendar view.  This worked fairly well, and for the money (did I mention it was free?) it couldn’t be beat.  But it is based on the stored job history in MSDB, and there were other performance problems that we ran into when we started changing the settings for how much job history to retain, in order to be able to look back a month or more in the calendar view.  Another coincidence (if you believe in such things) was that when we had some of those performance challenges, I posted a couple of questions to the #sqlhelp hashtag on Twitter and Greg Gonzalez (@SQLSensei) suggested I check out SQL Sentry’s Event Manager.  At the time, I just thought he worked there, but later found out that he founded the company.  When I took a quick look at the features & benefits, the one that really jumped out at me is Chaining and Queueing which sounded like it would really help with our “interdependent jobs on different servers” issue. I know that is a lot of background story and coincidences, but hopefully you have stuck with me so far, and now we have arrived at the point where last week I downloaded and installed the 30-day trial of the SQL Sentry Power Suite, which is Event Manager plus Performance Advisor.  And I must say that I really like what I see so far.  Here are a few highlights: Great Support.  I had two issues getting the trial setup and monitoring a handful of our servers.  One of which was entirely my fault (missed a security setting in SQL 2008) and the other was mostly my fault (late change to some config settings that were apparently cached and did not get refreshed properly).  In both cases, the support staff at SQL Sentry were very responsive and rather quickly figured out what the cause and fix was for each of them.  This left me with a great impression of the company.  Kudos to them! Chaining and Queueing.  While I have not yet activated this feature, I am very excited about the possibilities.  We have jobs on three different instances of SQL Server that have to be run in a certain order, and each has to finish before the next can successfully begin, and I believe this feature will ensure just that.  It has been a real pain in the backside when one of those jobs runs just a little too long and does not finish before the job on another instance starts, thus triggering a chain reaction of either outright job failures, or worse, successful completion of completely invalid processing. Calendar View.  I really, really like the Event Manager calendar view where I can see all jobs and events across all instances and identify potential resource contention as well as windows of opportunity for maintenance activity.  Very well done, and based on Event Manager’s own database of accumulated historical information rather than querying the source instances every time. Performance Advisor Dashboard History View.  This view let’s me quickly select a date and time range and it displays graphs of key SQL Server and Windows metrics.  This is exactly the thing I needed to answer the “has performance changed recently” question at the beginning of this post. Reporting Services Subscription Jobs with Report Name.  This was a big and VERY pleasant surprise.  If you have ever looked at the list of SQL Server jobs that SQL Server Reporting Services creates when you make a Subscription, you will notice that they all have some sort of GUID as the name of the job.  This is really ugly, and really annoying because when you are just looking at the SQL Agent and Job Activity Monitor, if you see that Job X failed, you really do not have any indication in the name or the properties of the Job itself, as to what Report that was for.  But with SQL Sentry Event Manager you do.  The Jobs list in the Navigator pane in SQL Sentry, amazingly, displays the name of the Report that the Subscription Job is for.  And when you open it to see more details, it shows you the full Reporting Services path to that Report, so you can immediately track it down in the Report Manager in case you want to identify/notify the owner or edit the Subscription information.  I did not expect this at all, but I sure do like it.  HOORAY! That is just my first impressions from using the tools for a few days.  And I haven’t even gotten into how it showed me where I was completely mistaken about one aspect of my SQL Server disk configurations.  I’ll share that lesson in another blog entry.  But I have to say it again, the combination of Event Manager and Performance Advisor working together have really made me a fan.

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  • External File Upload Optimizations for Windows Azure

    - by rgillen
    [Cross posted from here: http://rob.gillenfamily.net/post/External-File-Upload-Optimizations-for-Windows-Azure.aspx] I’m wrapping up a bit of the work we’ve been doing on data movement optimizations for cloud computing and the latest set of data yielded some interesting points I thought I’d share. The work done here is not really rocket science but may, in some ways, be slightly counter-intuitive and therefore seemed worthy of posting. Summary: for those who don’t like to read detailed posts or don’t have time, the synopsis is that if you are uploading data to Azure, block your data (even down to 1MB) and upload in parallel. Set your block size based on your source file size, but if you must choose a fixed value, use 1MB. Following the above will result in significant performance gains… upwards of 10x-24x and a reduction in overall file transfer time of upwards of 90% (eg, uploading a 1GB file averaged 46.37 minutes prior to optimizations and averaged 1.86 minutes afterwards). Detail: For those of you who want more detail, or think that the claims at the end of the preceding paragraph are over-reaching, what follows is information and code supporting these claims. As the title would indicate, these tests were run from our research facility pointing to the Azure cloud (specifically US North Central as it is physically closest to us) and do not represent intra-cloud results… we have performed intra-cloud tests and the overall results are similar in notion but the data rates are significantly different as well as the tipping points for the various block sizes… this will be detailed separately). We started by building a very simple console application that would loop through a directory and upload each file to Azure storage. This application used the shipping storage client library from the 1.1 version of the azure tools. The only real variation from the client library is that we added code to collect and record the duration (in ms) and size (in bytes) for each file transferred. The code is available here. We then created a directory that had a collection of files for the following sizes: 2KB, 32KB, 64KB, 128KB, 512KB, 1MB, 5MB, 10MB, 25MB, 50MB, 100MB, 250MB, 500MB, 750MB, and 1GB (50 files for each size listed). These files contained randomly-generated binary data and do not benefit from compression (a separate discussion topic). Our file generation tool is available here. The baseline was established by running the application described above against the directory containing all of the data files. This application uploads the files in a random order so as to avoid transferring all of the files of a given size sequentially and thereby spreading the affects of periodic Internet delays across the collection of results.  We then ran some scripts to split the resulting data and generate some reports. The raw data collected for our non-optimized tests is available via the links in the Related Resources section at the bottom of this post. For each file size, we calculated the average upload time (and standard deviation) and the average transfer rate (and standard deviation). As you likely are aware, transferring data across the Internet is susceptible to many transient delays which can cause anomalies in the resulting data. It is for this reason that we randomized the order of source file processing as well as executed the tests 50x for each file size. We expect that these steps will yield a sufficiently balanced set of results. Once the baseline was collected and analyzed, we updated the test harness application with some methods to split the source file into user-defined block sizes and then to upload those blocks in parallel (using the PutBlock() method of Azure storage). The parallelization was handled by simply relying on the Parallel Extensions to .NET to provide a Parallel.For loop (see linked source for specific implementation details in Program.cs, line 173 and following… less than 100 lines total). Once all of the blocks were uploaded, we called PutBlockList() to assemble/commit the file in Azure storage. For each block transferred, the MD5 was calculated and sent ensuring that the bits that arrived matched was was intended. The timer for the blocked/parallelized transfer method wraps the entire process (source file splitting, block transfer, MD5 validation, file committal). A diagram of the process is as follows: We then tested the affects of blocking & parallelizing the transfers by running the updated application against the same source set and did a parameter sweep on the block size including 256KB, 512KB, 1MB, 2MB, and 4MB (our assumption was that anything lower than 256KB wasn’t worth the trouble and 4MB is the maximum size of a block supported by Azure). The raw data for the parallel tests is available via the links in the Related Resources section at the bottom of this post. This data was processed and then compared against the single-threaded / non-optimized transfer numbers and the results were encouraging. The Excel version of the results is available here. Two semi-obvious points need to be made prior to reviewing the data. The first is that if the block size is larger than the source file size you will end up with a “negative optimization” due to the overhead of attempting to block and parallelize. The second is that as the files get smaller, the clock-time cost of blocking and parallelizing (overhead) is more apparent and can tend towards negative optimizations. For this reason (and is supported in the raw data provided in the linked worksheet) the charts and dialog below ignore source file sizes less than 1MB. (click chart for full size image) The chart above illustrates some interesting points about the results: When the block size is smaller than the source file, performance increases but as the block size approaches and then passes the source file size, you see decreasing benefit to the point of negative gains (see the values for the 1MB file size) For some of the moderately-sized source files, small blocks (256KB) are best As the size of the source file gets larger (see values for 50MB and up), the smallest block size is not the most efficient (presumably due, at least in part, to the increased number of blocks, increased number of individual transfer requests, and reassembly/committal costs). Once you pass the 250MB source file size, the difference in rate for 1MB to 4MB blocks is more-or-less constant The 1MB block size gives the best average improvement (~16x) but the optimal approach would be to vary the block size based on the size of the source file.    (click chart for full size image) The above is another view of the same data as the prior chart just with the axis changed (x-axis represents file size and plotted data shows improvement by block size). It again highlights the fact that the 1MB block size is probably the best overall size but highlights the benefits of some of the other block sizes at different source file sizes. This last chart shows the change in total duration of the file uploads based on different block sizes for the source file sizes. Nothing really new here other than this view of the data highlights the negative affects of poorly choosing a block size for smaller files.   Summary What we have found so far is that blocking your file uploads and uploading them in parallel results in significant performance improvements. Further, utilizing extension methods and the Task Parallel Library (.NET 4.0) make short work of altering the shipping client library to provide this functionality while minimizing the amount of change to existing applications that might be using the client library for other interactions.   Related Resources Source code for upload test application Source code for random file generator ODatas feed of raw data from non-optimized transfer tests Experiment Metadata Experiment Datasets 2KB Uploads 32KB Uploads 64KB Uploads 128KB Uploads 256KB Uploads 512KB Uploads 1MB Uploads 5MB Uploads 10MB Uploads 25MB Uploads 50MB Uploads 100MB Uploads 250MB Uploads 500MB Uploads 750MB Uploads 1GB Uploads Raw Data OData feeds of raw data from blocked/parallelized transfer tests Experiment Metadata Experiment Datasets Raw Data 256KB Blocks 512KB Blocks 1MB Blocks 2MB Blocks 4MB Blocks Excel worksheet showing summarizations and comparisons

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  • I see no LOBs!

    - by Paul White
    Is it possible to see LOB (large object) logical reads from STATISTICS IO output on a table with no LOB columns? I was asked this question today by someone who had spent a good fraction of their afternoon trying to work out why this was occurring – even going so far as to re-run DBCC CHECKDB to see if any corruption had taken place.  The table in question wasn’t particularly pretty – it had grown somewhat organically over time, with new columns being added every so often as the need arose.  Nevertheless, it remained a simple structure with no LOB columns – no TEXT or IMAGE, no XML, no MAX types – nothing aside from ordinary INT, MONEY, VARCHAR, and DATETIME types.  To add to the air of mystery, not every query that ran against the table would report LOB logical reads – just sometimes – but when it did, the query often took much longer to execute. Ok, enough of the pre-amble.  I can’t reproduce the exact structure here, but the following script creates a table that will serve to demonstrate the effect: IF OBJECT_ID(N'dbo.Test', N'U') IS NOT NULL DROP TABLE dbo.Test GO CREATE TABLE dbo.Test ( row_id NUMERIC IDENTITY NOT NULL,   col01 NVARCHAR(450) NOT NULL, col02 NVARCHAR(450) NOT NULL, col03 NVARCHAR(450) NOT NULL, col04 NVARCHAR(450) NOT NULL, col05 NVARCHAR(450) NOT NULL, col06 NVARCHAR(450) NOT NULL, col07 NVARCHAR(450) NOT NULL, col08 NVARCHAR(450) NOT NULL, col09 NVARCHAR(450) NOT NULL, col10 NVARCHAR(450) NOT NULL, CONSTRAINT [PK dbo.Test row_id] PRIMARY KEY CLUSTERED (row_id) ) ; The next script loads the ten variable-length character columns with one-character strings in the first row, two-character strings in the second row, and so on down to the 450th row: WITH Numbers AS ( -- Generates numbers 1 - 450 inclusive SELECT TOP (450) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) INSERT dbo.Test WITH (TABLOCKX) SELECT REPLICATE(N'A', N.n), REPLICATE(N'B', N.n), REPLICATE(N'C', N.n), REPLICATE(N'D', N.n), REPLICATE(N'E', N.n), REPLICATE(N'F', N.n), REPLICATE(N'G', N.n), REPLICATE(N'H', N.n), REPLICATE(N'I', N.n), REPLICATE(N'J', N.n) FROM Numbers AS N ORDER BY N.n ASC ; Once those two scripts have run, the table contains 450 rows and 10 columns of data like this: Most of the time, when we query data from this table, we don’t see any LOB logical reads, for example: -- Find the maximum length of the data in -- column 5 for a range of rows SELECT result = MAX(DATALENGTH(T.col05)) FROM dbo.Test AS T WHERE row_id BETWEEN 50 AND 100 ; But with a different query… -- Read all the data in column 1 SELECT result = MAX(DATALENGTH(T.col01)) FROM dbo.Test AS T ; …suddenly we have 49 LOB logical reads, as well as the ‘normal’ logical reads we would expect. The Explanation If we had tried to create this table in SQL Server 2000, we would have received a warning message to say that future INSERT or UPDATE operations on the table might fail if the resulting row exceeded the in-row storage limit of 8060 bytes.  If we needed to store more data than would fit in an 8060 byte row (including internal overhead) we had to use a LOB column – TEXT, NTEXT, or IMAGE.  These special data types store the large data values in a separate structure, with just a small pointer left in the original row. Row Overflow SQL Server 2005 introduced a feature called row overflow, which allows one or more variable-length columns in a row to move to off-row storage if the data in a particular row would otherwise exceed 8060 bytes.  You no longer receive a warning when creating (or altering) a table that might need more than 8060 bytes of in-row storage; if SQL Server finds that it can no longer fit a variable-length column in a particular row, it will silently move one or more of these columns off the row into a separate allocation unit. Only variable-length columns can be moved in this way (for example the (N)VARCHAR, VARBINARY, and SQL_VARIANT types).  Fixed-length columns (like INTEGER and DATETIME for example) never move into ‘row overflow’ storage.  The decision to move a column off-row is done on a row-by-row basis – so data in a particular column might be stored in-row for some table records, and off-row for others. In general, if SQL Server finds that it needs to move a column into row-overflow storage, it moves the largest variable-length column record for that row.  Note that in the case of an UPDATE statement that results in the 8060 byte limit being exceeded, it might not be the column that grew that is moved! Sneaky LOBs Anyway, that’s all very interesting but I don’t want to get too carried away with the intricacies of row-overflow storage internals.  The point is that it is now possible to define a table with non-LOB columns that will silently exceed the old row-size limit and result in ordinary variable-length columns being moved to off-row storage.  Adding new columns to a table, expanding an existing column definition, or simply storing more data in a column than you used to – all these things can result in one or more variable-length columns being moved off the row. Note that row-overflow storage is logically quite different from old-style LOB and new-style MAX data type storage – individual variable-length columns are still limited to 8000 bytes each – you can just have more of them now.  Having said that, the physical mechanisms involved are very similar to full LOB storage – a column moved to row-overflow leaves a 24-byte pointer record in the row, and the ‘separate storage’ I have been talking about is structured very similarly to both old-style LOBs and new-style MAX types.  The disadvantages are also the same: when SQL Server needs a row-overflow column value it needs to follow the in-row pointer a navigate another chain of pages, just like retrieving a traditional LOB. And Finally… In the example script presented above, the rows with row_id values from 402 to 450 inclusive all exceed the total in-row storage limit of 8060 bytes.  A SELECT that references a column in one of those rows that has moved to off-row storage will incur one or more lob logical reads as the storage engine locates the data.  The results on your system might vary slightly depending on your settings, of course; but in my tests only column 1 in rows 402-450 moved off-row.  You might like to play around with the script – updating columns, changing data type lengths, and so on – to see the effect on lob logical reads and which columns get moved when.  You might even see row-overflow columns moving back in-row if they are updated to be smaller (hint: reduce the size of a column entry by at least 1000 bytes if you hope to see this). Be aware that SQL Server will not warn you when it moves ‘ordinary’ variable-length columns into overflow storage, and it can have dramatic effects on performance.  It makes more sense than ever to choose column data types sensibly.  If you make every column a VARCHAR(8000) or NVARCHAR(4000), and someone stores data that results in a row needing more than 8060 bytes, SQL Server might turn some of your column data into pseudo-LOBs – all without saying a word. Finally, some people make a distinction between ordinary LOBs (those that can hold up to 2GB of data) and the LOB-like structures created by row-overflow (where columns are still limited to 8000 bytes) by referring to row-overflow LOBs as SLOBs.  I find that quite appealing, but the ‘S’ stands for ‘small’, which makes expanding the whole acronym a little daft-sounding…small large objects anyone? © Paul White 2011 email: [email protected] twitter: @SQL_Kiwi

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  • Learnings from trying to write better software: Loud errors from the very start

    - by theo.spears
    Microsoft made a very small number of backwards incompatible changes between .NET 1.1 and 2.0, because they wanted to make it as easy and safe as possible to port applications to the new runtime. (Here’s a list.) However, one thing they did change was what happens when a background thread fails with an unhanded exception - in .NET 1.1 nothing happened, the thread terminated, and the application continued oblivious. Try the same trick in .NET 2.0 and the entire application, including all threads, will rudely terminate. There are three reasons for this. Firstly if a background thread has crashed, it may have left the entire application in an inconsistent state, in a way that will affect other threads. It’s better to terminate the entire application than continue and have the application perform actions based on a broken state, for example take customer orders, or write corrupt files to disk.  Secondly, during software development, it is far better for errors to be loud and obtrusive. Even if you have unit tests and integration tests (and you should), a key part of ensuring software works properly is to actually try using it, both through systematic testing and through the casual use all software gets by its developers during use. Subtle errors are easy to miss if you are not actually doing real work using the application, loud errors are obvious. Thirdly, and most importantly, even if catching and swallowing exceptions indiscriminately doesn't cause any problems in your application, the presence of unexpected exceptions shows you do not fully understand the behavior of your code. The currently released version of your application may be absolutely correct. However, because your mental model of the behavior is wrong, any future change you make to the program could and probably will introduce critical errors.  This applies to more than just exceptions causing threads to exit, any unexpected state should make the application blow up in an un-ignorable way. The worst thing you can do is silently swallow errors and continue. And let's be clear, writing to a log file does not count as blowing up in an un-ignorable way.  This is all simple as long as the call stack only contains your code, but when your functions start to be called by third party or .NET framework code, it's surprisingly easy for exceptions to start vanishing. Let's look at two examples.   1. Windows forms drag drop events  Usually if you throw an exception from a winforms event handler it will bring up the "application has crashed" dialog with abort and continue options. This is a good default behavior - the error is big and loud, but it is possible for the user to ignore the error and hopefully save their data, if somehow this bug makes it past testing. However drag and drop are different - throw an exception from one of these and it will just be silently swallowed with no explanation.  By the way, it's not just drag and drop events. Timer events do it too.  You can research how exceptions are treated in different handlers and code appropriately, but the safest and most user friendly approach is to always catch exceptions in your event handlers and show your own error message. I'll talk about one good approach to handling these exceptions at the end of this post.   2. SSMS integration for SQL Tab Magic  A while back wrote an SSMS add-in called SQL Tab Magic (learn more about the process here). It works by listening to certain SSMS events and remembering what documents are opened and closed. I deployed it internally and it was used for a few months by a number of people without problems, so I was reasonably confident in its quality. Before releasing I made a few cleanups, including introducing error reporting. Bam. A few days later I was looking at over 1,000 error reports in my inbox. In turns out I wasn't handling table designers properly. The exceptions were there, but again SSMS was helpfully swallowing them all for me, so I was blissfully unaware. Had I made my errors loud from the start, I would have noticed these issues long before and fixed them.   Handling exceptions  Now you are systematically catching exceptions throughout your application, you need to do something with them. I've tried 3 options: log them, alert the user, and automatically send them home.  There are a few good options for logging in .NET. The most widespread is Apache log4net, which provides a very capable and configurable logging framework. There is also NLog which has a compatible interface, with a greater emphasis on fluent rather than XML configuration.  Alerting the user serves two purposes. Firstly it means they understand their action has failed to they don't just assume it worked (Silent file copy failure is a problem if you then delete the originals) or that they should keep waiting for a background task to complete. Secondly, it means the users can report the bug to your support team, and then you can fix it. This means the message you show the user should contain the information you need as a developer to identify and fix it. And the user will probably just send you a screenshot of the dialog, so it shouldn't be hidden by scroll bars.  This leads us to the third option, automatically sending error reports home. By automatic I mean with minimal effort on the part of the user, rather than doing it silently behind their backs. The advantage of this is you can send back far more detailed and precise information than you can expect a user to include in an email, and by making it easier to report errors, you make it more likely users will do so.  We do this using a great tool called SmartAssembly (full disclosure: this is a product made by Red Gate). It captures complete stack traces including the values of all local variables and then allows the user to send all this information back with a single click. We also capture log files to help understand what lead up to the error. We then use the free SmartAssembly Sync for Jira to dedupe these reports and raise them as bugs in our bug tracking system.  The combined effect of loud errors during development and then automatic error reporting once software is deployed allows us to find and fix more bugs, correct misunderstandings on how our software works, and overall is a key piece in delivering higher quality software. However it is no substitute for having motivated cunning testers in the building - and we're looking to hire more of those too.   If you found this post interesting you should follow me on twitter.  

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  • first install for windows eight.....da beta

    - by raysmithequip
    The W8 preview is now installed and I am enjoying it.  I remember the learning curve of my first unix machine back in the eighties, this ain't that.It is normal for me to do the first os install with a keyboard and low end monitor...you never know what you'll encounter out in the field.  The OS took like a fish to water.  I used a low end INTEL motherboard dp55w I gathered on the cheap, an 1157 i5 from the used bin a pair of 6 gig ddr3 sticks, a rosewell 550 watt power supply a cheap used twenty buck sub 200g wd sata drive, a half working dvd burner and an asus fanless nvidia vid card, not a great one but Sub 50.00 on newey eggey...I did have to hunt the ms forums for a key and of course to activate the thing, if dos would of needed this outmoded ritual, we would still be on cpm and osborne would be a household name, of course little do people know that this ritual was common as far back as the seventies on att unix installs....not, but it was possible, I used to joke about when I ran a bbs, what hell would of been wrought had dos 3.2 machines been required to dial into my bbs to send fido mail to ms and wait for an acknowledgement.  All in all the thing was pushing a seven on the ms richter scale, not including the vid card, sadly it came in at just a tad over three....I wanted to evaluate it for a possible replacement on critical machines that in the past went down due to a vid card fan failure....you have no idea what a customer thinks when you show them a failed vid card fan..."you mean that little plastic piece of junk caused all this!!??!!!"...yea man.  Some production machines don't need any sort of vid, I will at least keep it on the maybe list for those, MTBF is a very important factor, some big box stores should put percentage of failure rate within 24 month estimates on the outside of the carton for sure.  And a warning that the power supplies are already at their limit.  Let's face it, today even 550w can be iffy.A few neat eye candy improvements over the earlier windows is nice, the metro screen is nice, anyone who has used a newer phone recently will intuitively drag their fingers across the screen....lot of good that was with no mouse or touch screen though.  Lucky me, I have been using windows since day one, I still have a copy of win 2.0 (and every other version) for no good reason.  Still the old ix collection of disks is much larger, recompiling any kernal is another silly ritual, same machine, different day, same recompile...argh. Rh is my all time fav, mandrake was always missing something, like it rewrote the init file or something, novell is ok as long as you stay on the beaten path and of course ubuntu normally recompiles with the same errors consistantly....makes life easy that way....no errors on windows eight, just a screen that did not match the installed hardware, natuarally I alt tabbed right out of it, then hit the flag key to find the start menu....no start button. I miss the start button already. Keyboard cowboy funnin and I was browsing the harddrive, nothing stunning there, I like that, means I can find stuff. Only I can't find what I want, the start button....the start menu is that first screen for touch tablets. No biggie for useruser, that is where they will want to be, I can see that. Admins won't want to be there, it is easy enough to get the control panel a bazzilion other ways though, just not the start button. (see a pattern here?). Personally, from the keyboard I find it fun to hit the carets along the location bar at the top of the explorer screen with tabs and arrows and choose SHOW ALL CONTROL PANEL ITEMS, or thereabouts. Bottom line, I love seven and I'll love eight even more!...very happy I did not have to follow the normal rule of thumb (a customer watching me build a system and asking questions said "oh I get it, so every piece you put in there is basically a hundred bucks, right?)...ok, sure, pretty much, more or less, well, ya dude.  It will be WAY past october till I get a real touch screen but I did pick up a pair of cheap tatungs so I can try the NEW main start screen, I parse a lot of folders and have a vision of how a pair of touch screens will be easier than landing a rover on mars.  Ok.  fine, they are way smallish, and I don't expect multitouch to work but we are talking a few percent of a new 21 inch viewsonic touch screen.  Will this OS be a game changer?  I don't know.  Bottom line with all the pads and droids in the world, it is more of a catch up move at first glance.  Not something ms is used to.  An app store?  I can see ms's motivation, the others have it.  I gather there will not be gadgets there, go ahead and see what ms did  to the once populated gadget page...go ahead, google gadgets and take a gander, used to hundreds of gadgets, they are already gone.  They replaced gadgets?  sort of, I'll drop that, it's a bit of a sore point for me.  More of interest was what happened when I downloaded stuff off codeplex and some other normal programs that I like, like orbitron, top o' my list!!...cardware it is...anyways, click on the exe, get a screen, normal for windows, this one indicated that I was not running a normal windows program and had a button for  exit the install, naw, I hit details, a hidden run program anyways came into view....great, my path to the normal windows has detected a program tha.....yea ok, acl is on, fine, moving along I got orbitron installed in record time and was tracking the iss on the newest Microsoft OS, beta of course, felt like the first time I setup bsd all those year ago...FUN!!...I suppose I gotta start to think about budgeting for the real os when it comes out in october, by then I should have a rasberry pi and be done with fedora remixed.  Of course that sounds like fun too!!  I would use this OS on a tablet or phone.  I don't like the idea of being hearded to an app store, don't like that on anything, we are americans and want real choices not marketed hype, lest you are younger with opm (other peoples money).   This os would be neat on a zune, but I suspect the zune is a gonner, I am rooting for microsoft, after all their default password is not admin anymore, nor alpine,  it's blank. Others force a password, my first fawn password was so long I could not even log into it with the password in front of me, who the heck uses %$# anyways, and if I was writing a brute force attack what the heck kinda impasse is that anyways at .00001 microseconds of a code execution cycle (just a non qualified number, not a real clock speed)....AI is where it will be before too long, MS is on that path, perhaps soon someone will sit down and write an app for the kinect that watches your eyes while you scan the new main start screen, clicking on the big E icon when you blink.....boy is that going to be fun!!!! sure. Blink,dammit,blink,dammit...... OPM no doubt.I like windows eight, we are moving forwards, better keep a close eye on ubuntu.  The real clinch comes when open source becomes paid source......don't blink, I already see plenty of very expensive 'ix apps, some even in app stores already.  more to come.......

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Book Review: Brownfield Application Development in .NET

    - by DotNetBlues
    I recently finished reading the book Brownfield Application Development in .NET by Kyle Baley and Donald Belcham.  The book is available from Manning.  First off, let me say that I'm a huge fan of Manning as a publisher.  I've found their books to be top-quality, over all.  As a Kindle owner, I also appreciate getting an ebook copy along with the dead tree copy.  I find ebooks to be much more convenient to read, but hard-copies are easier to reference. The book covers, surprisingly enough, working with brownfield applications.  Which is well and good, if that term has meaning to you.  It didn't for me.  Without retreading a chunk of the first chapter, the authors break code bases into three broad categories: greenfield, brownfield, and legacy.  Greenfield is, essentially, new development that hasn't had time to rust and is (hopefully) being approached with some discipline.  Legacy applications are those that are more or less stable and functional, that do not expect to see a lot of work done to them, and are more likely to be replaced than reworked. Brownfield code is the gray (brown?) area between the two and the authors argue, quite effectively, that it is the most likely state for an application to be in.  Brownfield code has, in some way, been allowed to tarnish around the edges and can be difficult to work with.  Although I hadn't realized it, most of the code I've worked on has been brownfield.  Sometimes, there's talk of scrapping and starting over.  Sometimes, the team dismisses increased discipline as ivory tower nonsense.  And, sometimes, I've been the ignorant culprit vexing my future self. The book is broken into two major sections, plus an introduction chapter and an appendix.  The first section covers what the authors refer to as "The Ecosystem" which consists of version control, build and integration, testing, metrics, and defect management.  The second section is on actually writing code for brownfield applications and discusses object-oriented principles, architecture, external dependencies, and, of course, how to deal with these when coming into an existing code base. The ecosystem section is just shy of 140 pages long and brings some real meat to the matter.  The focus on "pain points" immediately sets the tone as problem-solution, rather than academic.  The authors also approach some of the topics from a different angle than some essays I've read on similar topics.  For example, the chapter on automated testing is on just that -- automated testing.  It's all well and good to criticize a project as conflating integration tests with unit tests, but it really doesn't make anyone's life better.  The discussion on testing is more focused on the "right" level of testing for existing projects.  Sometimes, an integration test is the best you can do without gutting a section of functional code.  Even if you can sell other developers and/or management on doing so, it doesn't actually provide benefit to your customers to rewrite code that works.  This isn't to say the authors encourage sloppy coding.  Far from it.  Just that they point out the wisdom of ignoring the sleeping bear until after you deal with the snarling wolf. The other sections take a similarly real-world, workable approach to the pain points they address.  As the section moves from technical solutions like version control and continuous integration (CI) to the softer, process issues of metrics and defect tracking, the authors begin to gently suggest moving toward a zero defect count.  While that really sounds like an unreasonable goal for a lot of ongoing projects, it's quite apparent that the authors have first-hand experience with taming some gruesome projects.  The suggestions are grounded and workable, and the difficulty of some situations is explicitly acknowledged. I have to admit that I started getting bored by the end of the ecosystem section.  No matter how valuable I think a good project manager or business analyst is to a successful ALM, at the end of the day, I'm a gear-head.  Also, while I agreed with a lot of the ecosystem ideas, in theory, I didn't necessarily feel that a lot of the single-developer projects that I'm often involved in really needed that level of rigor.  It's only after reading the sidebars and commentary in the coding section that I had the context for the arguments made in favor of a strong ecosystem supporting the development process.  That isn't to say that I didn't support good product management -- indeed, I've probably pushed too hard, on occasion, for a strong ALM outside of just development.  This book gave me deeper insight into why some corners shouldn't be cut and how damaging certain sins of omission can be. The code section, though, kept me engaged for its entirety.  Many technical books can be used as reference material from day one.  The authors were clear, however, that this book is not one of these.  The first chapter of the section (chapter seven, over all) addresses object oriented (OO) practices.  I've read any number of definitions, discussions, and treatises on OO.  None of the chapter was new to me, but it was a good review, and I'm of the opinion that it's good to review the foundations of what you do, from time to time, so I didn't mind. The remainder of the book is really just about how to apply OOP to existing code -- and, just because all your code exists in classes does not mean that it's object oriented.  That topic has the potential to be extremely condescending, but the authors miraculously managed to never once make me feel like a dolt or that they were wagging their finger at me for my prior sins.  Instead, they continue the "pain points" and problem-solution presentation to give concrete examples of how to apply some pretty academic-sounding ideas.  That's a point worth emphasizing, as my experience with most OO discussions is that they stay in the academic realm.  This book gives some very, very good explanations of why things like the Liskov Substitution Principle exist and why a corporate programmer should even care.  Even if you know, with absolute certainty, that you'll never have to work on an existing code-base, I would recommend this book just for the clarity it provides on OOP. This book goes beyond just theory, or even real-world application.  It presents some methods for fixing problems that any developer can, and probably will, encounter in the wild.  First, the authors address refactoring application layers and internal dependencies.  Then, they take you through those layers from the UI to the data access layer and external dependencies.  Finally, they come full circle to tie it all back to the overall process.  By the time the book is done, you're left with a lot of ideas, but also a reasonable plan to begin to improve an existing project structure. Throughout the book, it's apparent that the authors have their own preferred methodology (TDD and domain-driven design), as well as some preferred tools.  The "Our .NET Toolbox" is something of a neon sign pointing to that latter point.  They do not beat the reader over the head with anything resembling a "One True Way" mentality.  Even for the most emphatic points, the tone is quite congenial and helpful.  With some of the near-theological divides that exist within the tech community, I found this to be one of the more remarkable characteristics of the book.  Although the authors favor tools that might be considered Alt.NET, there is no reason the advice and techniques given couldn't be quite successful in a pure Microsoft shop with Team Foundation Server.  For that matter, even though the book specifically addresses .NET, it could be applied to a Java and Oracle shop, as well.

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  • Possible SWITCH Optimization in DAX – #powerpivot #dax #tabular

    - by Marco Russo (SQLBI)
    In one of the Advanced DAX Workshop I taught this year, I had an interesting discussion about how to optimize a SWITCH statement (which could be frequently used checking a slicer, like in the Parameter Table pattern). Let’s start with the problem. What happen when you have such a statement? Sales :=     SWITCH (         VALUES ( Period[Period] ),         "Current", [Internet Total Sales],         "MTD", [MTD Sales],         "QTD", [QTD Sales],         "YTD", [YTD Sales],          BLANK ()     ) The SWITCH statement is in reality just syntax sugar for a nested IF statement. When you place such a measure in a pivot table, for every cell of the pivot table the IF options are evaluated. In order to optimize performance, the DAX engine usually does not compute cell-by-cell, but tries to compute the values in bulk-mode. However, if a measure contains an IF statement, every cell might have a different execution path, so the current implementation might evaluate all the possible IF branches in bulk-mode, so that for every cell the result from one of the branches will be already available in a pre-calculated dataset. The price for that could be high. If you consider the previous Sales measure, the YTD Sales measure could be evaluated for all the cells where it’s not required, and also when YTD is not selected at all in a Pivot Table. The actual optimization made by the DAX engine could be different in every build, and I expect newer builds of Tabular and Power Pivot to be better than older ones. However, we still don’t live in an ideal world, so it could be better trying to help the engine finding a better execution plan. One student (Niek de Wit) proposed this approach: Selection := IF (     HASONEVALUE ( Period[Period] ),     VALUES ( Period[Period] ) ) Sales := CALCULATE (     [Internet Total Sales],     FILTER (         VALUES ( 'Internet Sales'[Order Quantity] ),         'Internet Sales'[Order Quantity]             = IF (                 [Selection] = "Current",                 'Internet Sales'[Order Quantity],                 -1             )     ) )     + CALCULATE (         [MTD Sales],         FILTER (             VALUES ( 'Internet Sales'[Order Quantity] ),             'Internet Sales'[Order Quantity]                 = IF (                     [Selection] = "MTD",                     'Internet Sales'[Order Quantity],                     -1                 )         )     )     + CALCULATE (         [QTD Sales],         FILTER (             VALUES ( 'Internet Sales'[Order Quantity] ),             'Internet Sales'[Order Quantity]                 = IF (                     [Selection] = "QTD",                     'Internet Sales'[Order Quantity],                     -1                 )         )     )     + CALCULATE (         [YTD Sales],         FILTER (             VALUES ( 'Internet Sales'[Order Quantity] ),             'Internet Sales'[Order Quantity]                 = IF (                     [Selection] = "YTD",                     'Internet Sales'[Order Quantity],                     -1                 )         )     ) At first sight, you might think it’s impossible that this approach could be faster. However, if you examine with the profiler what happens, there is a different story. Every original IF’s execution branch is now a separate CALCULATE statement, which applies a filter that does not execute the required measure calculation if the result of the FILTER is empty. I used the ‘Internet Sales’[Order Quantity] column in this example just because in Adventure Works it has only one value (every row has 1): in the real world, you should use a column that has a very low number of distinct values, or use a column that has always the same value for every row (so it will be compressed very well!). Because the value –1 is never used in this column, the IF comparison in the filter discharge all the values iterated in the filter if the selection does not match with the desired value. I hope to have time in the future to write a longer article about this optimization technique, but in the meantime I’ve seen this optimization has been useful in many other implementations. Please write your feedback if you find scenarios (in both Power Pivot and Tabular) where you obtain performance improvements using this technique!

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  • Exception Handling And Other Contentious Political Topics

    - by Justin Jones
    So about three years ago, around the time of my last blog post, I promised a friend I would write this post. Keeping promises is a good thing, and this is my first step towards easing back into regular blogging. I fully expect him to return from Pennsylvania to buy me a beer over this. However, it’s been an… ahem… eventful three years or so, and blogging, unfortunately, got pushed to the back burner on my priority list, along with a few other career minded activities. Now that the personal drama of the past three years is more or less resolved, it’s time to put a few things back on the front burner. What I consider to be proper exception handling practices is relatively well known these days. There are plenty of blog posts out there already on this topic which more or less echo my opinions on this topic. I’ll try to include a few links at the bottom of the post. Several years ago I had an argument with a co-worker who posited that exceptions should be caught at every level and logged. This might seem like sanity on the surface, but the resulting error log looked something like this: Error: System.SomeException Followed by small stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace.   These were all the same exception. The problem with this approach is that the error log, if you run any kind of analytics on in, becomes skewed depending on how far up the stack trace your exception was thrown. To mitigate this problem, we came up with the concept of the “PreLoggedException”. Basically, we would log the exception at the very top level and subsequently throw the exception back up the stack encapsulated in this pre-logged type, which our logging system knew to ignore. Now the error log looked like this: Error: System.SomeException Followed by small stack trace. Much cleaner, right? Well, there’s still a problem. When your exception happens in production and you go about trying to figure out what happened, you’ve lost more or less all context for where and how this exception was thrown, because all you really know is what method it was thrown in, but really nothing about who was calling the method or why. What gives you this clue is the entire stack trace, which we’re losing here. I believe that was further mitigated by having the logging system pull a system stack trace and add it to the log entry, but what you’re actually getting is the stack for how you got to the logging code. You’re still losing context about the actual error. Not to mention you’re executing a whole slew of catch blocks which are sloooooooowwwww……… In other words, we started with a bad idea and kept band-aiding it until it didn’t suck quite so bad. When I argued for not catching exceptions at every level but rather catching them following a certain set of rules, my co-worker warned me “do yourself a favor, never express that view in any future interviews.” I suppose this is my ultimate dismissal of that advice, but I’m not too worried. My approach for exception handling follows three basic rules: Only catch an exception if 1. You can do something about it. 2. You can add useful information to it. 3. You’re at an application boundary. Here’s what that means: 1. Only catch an exception if you can do something about it. We’ll start with a trivial example of a login system that uses a file. Please, never actually do this in production code, it’s just concocted example. So if our code goes to open a file and the file isn’t there, we get a FileNotFound exception. If the calling code doesn’t know what to do with this, it should bubble up. However, if we know how to create the file from scratch we can create the file and continue on our merry way. When you run into situations like this though, What should really run through your head is “How can I avoid handling an exception at all?” In this case, it’s a trivial matter to simply check for the existence of the file before trying to open it. If we detect that the file isn’t there, we can accomplish the same thing without having to handle in in a catch block. 2. Only catch an exception if you can do something about it. Continuing with the poorly thought out file based login system we contrived in part 1, if the code calls a Login(…) method and the FileNotFound exception is thrown higher up the stack, the code that calls Login must account for a FileNotFound exception. This is kind of counterintuitive because the calling code should not need to know the internals of the Login method, and the data file is an implementation detail. What makes more sense, assuming that we didn’t implement any of the good advice from step 1, is for Login to catch the FileNotFound exception and wrap it in a new exception. For argument’s sake we’ll say LoginSystemFailureException. (Sorry, couldn’t think of anything better at the moment.) This gives us two stack traces, preserving the original stack trace in the inner exception, and also is much more informative to the calling code. 3. Only catch an exception if you’re at an application boundary. At some point we have to catch all the exceptions, even the ones we don’t know what to do with. WinForms, ASP.Net, and most other UI technologies have some kind of built in mechanism for catching unhandled exceptions without fatally terminating the application. It’s still a good idea to somehow gracefully exit the application in this case if possible though, because you can no longer be sure what state your application is in, but nothing annoys a user more than an application just exploding. These unhandled exceptions need to be logged, and this is a good place to catch them. Ideally you never want this option to be exercised, but code as though it will be. When you log these exceptions, give them a “Fatal” status (e.g. Log4Net) and make sure these bugs get handled in your next release. That’s it in a nutshell. If you do it right each exception will only get logged once and with the largest stack trace possible which will make those 2am emergency severity 1 debugging sessions much shorter and less frustrating. Here’s a few people who also have interesting things to say on this topic:  http://blogs.msdn.com/b/ericlippert/archive/2008/09/10/vexing-exceptions.aspx http://www.codeproject.com/Articles/9538/Exception-Handling-Best-Practices-in-NET I know there’s more but I can’t find them at the moment.

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