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  • Python sqlite3 and concurrency

    - by RexE
    I have a Python program that uses the "threading" module. Once every second, my program starts a new thread that fetches some data from the web, and stores this data to my hard drive. I would like to use sqlite3 to store these results, but I can't get it to work. The issue seems to be about the following line: conn = sqlite3.connect("mydatabase.db") If I put this line of code inside each thread, I get an OperationalError telling me that the database file is locked. I guess this means that another thread has mydatabase.db open through a sqlite3 connection and has locked it. If I put this line of code in the main program and pass the connection object (conn) to each thread, I get a ProgrammingError, saying that SQLite objects created in a thread can only be used in that same thread. Previously I was storing all my results in CSV files, and did not have any of these file-locking issues. Hopefully this will be possible with sqlite. Any ideas?

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  • How to generate distinct random numbers per distinct threads in .NET?

    - by mark
    Dear ladies and sirs. I have to generate 19 bit random numbers. However, there is a constraint - two threads may not generate the same random number when running certain code. The simplest solution is lock the entire code. However, I would like to know if there is a non locking solution. I thought, I can incorporate ManagedThreadId within the produced random numbers, but the ManagedThreadId documentation on the Internet mentions that it may span the whole Int32 range. Unmanaged thread id seems to be limited to 11 bits, still this leaves me with just 8 truly random bits. Are there any other ways? Somehow to utilize the Thread Local Storage, may be? Thanks.

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  • Can ANYONE get _lockroot to work?

    - by webfac
    Hi Guys, I have the following code which ultimately loads a SWF into movieclip 'myloader' using a movie clip loader, code as follows: var myload:MovieClipLoader = new MovieClipLoader(); var listener:Object = new Object(); myload.addListener(listener); listener.onLoadStart = function(){ animcontainer.myloader._lockroot = true; trace("Started"); } listener.onLoadInit = function(){ animcontainer.myloader._lockroot = true; trace("finished and locked"); } listener.onLoadComplete = function(){ animcontainer.myloader._lockroot = true; } myload.loadClip(path, animcontainer.myloader); The swf I am loading has pause, rewind and play buttons that must be referencing _root as they work fine when played alone. Upon loading them into myloader they no longer work. Based on the above code surely the myloader clip should be locking as _root after the load is complete? I have Googled myself dry on this one, no luck. ANY help will be much appreciated, Thanks.

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  • MySQL features I can rely on being available

    - by xrstf
    So I'm developing a PHP/MySQL based CMS which requires PHP 5.1 and MySQL 5.0 (with InnoDB support) at least. I'm now wondering what features of MySQL I can safely use without noticing one day that "Oh, well, that crappy hoster has disabled feature X, damn, now I'm screwed." So my question is, which of these features can become problematic (= can be disabled, require special configuration, require user privilege): transactions and FKs in InnoDB (of course unavailable to MyISAM) table locking (MyISAM and InnoDB) stored procedures I just want to know once and for all what's the minimal feature set I can expect from MySQL.

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  • Can a thread call wait() on two locks at once in Java (6)

    - by Dr. Monkey
    I've just been messing around with threads in Java to get my head around them (it seems like the best way to do so) and now understand what's going on with synchronize, wait() and notify(). I'm curious about whether there's a way to wait() on two resources at once. I think the following won't quite do what I'm thinking of: synchronized(token1) { synchronized(token2) { token1.wait(); token2.wait(); //won't run until token1 is returned System.out.println("I got both tokens back"); } } In this (very contrived) case token2 will be held until token1 is returned, then token1 will be held until token2 is returned. The goal is to release both token1 and token2, then resume when both are available (note that moving the token1.wait() outside the inner synchronized loop is not what I'm getting at). A loop checking whether both are available might be more appropriate to achieve this behaviour (would this be getting near the idea of double-check locking?), but would use up extra resources - I'm not after a definitive solution since this is just to satisfy my curiosity.

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  • Exception for java Swing application?

    - by Rich Fluckiger
    For some reason this is locking up the java application. Did I handle the exception correctly? private void submitButtonActionPerformed(java.awt.event.ActionEvent evt) { double amount, interest,rateCalc, a, b, c, payment; int years, months; while (true){ try{ amount = Double.valueOf(loanAmount.getText()); interest = Double.valueOf(interestRate.getText()); years = Integer.valueOf(loanYears.getText()); rateCalc = (interest/12); months = (years*12); a = Math.pow((1+rateCalc),months); b = (a*rateCalc); c = (a-1); payment = (amount *(b/c)); monthlyPayment.setText("Mortgage Payment $ = " + payment); } catch (NumberFormatException nfe){ javax.swing.JOptionPane.showMessageDialog(null, "Please enter numbers and not letters"); return; } } } monthlyPayment returns to the java app.

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  • SQL Server 2005 Transactions

    - by mcallec
    I have a long running stored proc (approx 30 mins) which is currently running within a transaction (isolation level snapshot). I've set the transaction to snapshot to avoid locking records preventing other processes from accessing the data. What I'm trying to do is write to and read from a status table, but although we're in a transaction I'd like to write to and read from the status table as if I'm not in a transaction. I need this so that other processes can read any updates to this table by my stored proc, and this stored proc can also read any inserts made by other processes. I realise that having my entire stored proc running within a transaction isn't recommended, but this has been done for other reasons and we need to stick with that approach. So my question is within a transaction, is it possible to execute a query or call a stored proc which effectively isn't enlisted in the transaction?

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  • How to know when a user console is locked or has logged "back into" windows

    - by Paul Kohler
    This is in regards to applications that run in the taskbar but should be applicable to standard apps, Winforms, WPF, etc. Question: I am after some method (preferably via managed code) to be notified when a user either has their screen "locked" while my app is running and/or know when they log back in. GMail Notifier does this sort of thing for example, if my PC is locked for a while when I log in again it shows a list of emails that arrived since locking the PC. I'm looking to replicate that kind of functionality. Does anyone have any ideas on how to accomplish this?

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  • Mysql with innodb and serializable transaction does not (always) lock rows

    - by Tobias G.
    Hello, I have a transaction with a SELECT and possible INSERT. For concurrency reasons, I added FOR UPDATE to the SELECT. To prevent phantom rows, I'm using the SERIALIZABLE transaction isolation level. This all works fine when there are any rows in the table, but not if the table is empty. When the table is empty, the SELECT FOR UPDATE does not do any (exclusive) locking and a concurrent thread/process can issue the same SELECT FOR UPDATE without being locked. CREATE TABLE t ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, display_order INT ) ENGINE = InnoDB; SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; START TRANSACTION; SELECT COALESCE(MAX(display_order), 0) + 1 from t FOR UPDATE; .. This concept works as expected with SQL Server, but not with MySQL. Any ideas on what I'm doing wrong? EDIT Adding an index on display_order does not change the behavior.

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  • Advanced Registry Monitoring

    - by RyanTimmons91
    I'm attempting to create a small utility to watch for the creation (or modification) of a specific registry key, and to kill the process responsible for causing that registry modification. I have had success in watching the changes to the registry via a class called 'RegistryMonitor', however it does not give you any information on what process initiated the registry call, through some googling I found that a library called 'EasyHook' should be able to do what I want, but all the documentation states that its designed for a per-application hook. The program itself is a temporary security patch, until our vendors come out with an official security update. As best I can tell there isn't a way to do exactly what I want to accomplish from C#, which is the only language I can comfortable write, test and execute software in. Any help on this would be appreciated I'm considering watching the registry changes via the program I already have, then if the change is discovered (the pc is already infected) running RKill and locking down the PC to prevent the issue from getting any worse

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  • Grounded in Dublin

    - by Mike Dietrich
    Friday's hands-on workshop in the Oracle office in Dublin was quite good fun for everybody - except for Mick who has just recognized that his Ryanair flight back to Cork has been canceled (So I hope you've returned home well!) and me as my flights back to Munich via London City had been canceled as well. It's always good to have somebody in the workshop from Air Lingus so I've got hourly information what's going in in the Irish airspace (and now I know that the system dealing with such situations is an well prepared Oracle database which runs just like a switch watch - Thanks again for all your support!!! Was great to talk to you!!!). But to be honest, there are worse places to be grounded for a few days than Dublin. At least it gave me the chance to do something which I never had time enough before when visiting Oracle Ireland: a bit of sightseeing. When I've realized that nothing seems to move over the weekend I started organizing my travel back yesterday. It was no fun at all because there's no single system to book such a travel. Figuring out all possibilities and options going back to Munich was the first challange. Irish Ferries webpage was moaning with all the unexpected load (currently it's fully down). Hotel booking websites showed vacancies in Holyhead but didn't let me book. And calling them just reveiled that there are no rooms left. Haven't stayed overnight in a train station for quite a while ;-) The website of VirginTrains puzzled me with offering a seat at an enormous price for a train ride from Holyhead to London Euston (Thanks, Sir Richard Branson!) just to tell me after I booked a ticket that there are no seats left (but I traveled German railsways a few weeks ago from Düsseldorf to Frankfurt sitting on the floor as well). Eurostar's website let me choose tickets through the tunnel to tell me in the final step that the ticket cannot be confirmed as there are no seats left - but the next check again showed bookable seats - must be a database from some other vendor which has no proper row level locking ... hm ...?! Finally the TGV page for the speed train to Stuttgart and then the ICE to Munich was not allowing searches for quite a while - but ultimately ... after 4.5 hours of searching, waiting, sending credit card information again and again ... So if you have a few spare fingers please keep them crossed :-) And good luck to all my colleagues traveling back from the Exadata training in Berlin. As Mike Appleyard, my colleague from the UK presales team wrote: "Dublin and Berlin aren't too bad a place to get stuck... ;-)"

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  • SQL SERVER – Simple Example of Snapshot Isolation – Reduce the Blocking Transactions

    - by pinaldave
    To learn any technology and move to a more advanced level, it is very important to understand the fundamentals of the subject first. Today, we will be talking about something which has been quite introduced a long time ago but not properly explored when it comes to the isolation level. Snapshot Isolation was introduced in SQL Server in 2005. However, the reality is that there are still many software shops which are using the SQL Server 2000, and therefore cannot be able to maintain the Snapshot Isolation. Many software shops have upgraded to the later version of the SQL Server, but their respective developers have not spend enough time to upgrade themselves with the latest technology. “It works!” is a very common answer of many when they are asked about utilizing the new technology, instead of backward compatibility commands. In one of the recent consultation project, I had same experience when developers have “heard about it” but have no idea about snapshot isolation. They were thinking it is the same as Snapshot Replication – which is plain wrong. This is the same demo I am including here which I have created for them. In Snapshot Isolation, the updated row versions for each transaction are maintained in TempDB. Once a transaction has begun, it ignores all the newer rows inserted or updated in the table. Let us examine this example which shows the simple demonstration. This transaction works on optimistic concurrency model. Since reading a certain transaction does not block writing transaction, it also does not block the reading transaction, which reduced the blocking. First, enable database to work with Snapshot Isolation. Additionally, check the existing values in the table from HumanResources.Shift. ALTER DATABASE AdventureWorks SET ALLOW_SNAPSHOT_ISOLATION ON GO SELECT ModifiedDate FROM HumanResources.Shift GO Now, we will need two different sessions to prove this example. First Session: Set Transaction level isolation to snapshot and begin the transaction. Update the column “ModifiedDate” to today’s date. -- Session 1 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN UPDATE HumanResources.Shift SET ModifiedDate = GETDATE() GO Please note that we have not yet been committed to the transaction. Now, open the second session and run the following “SELECT” statement. Then, check the values of the table. Please pay attention on setting the Isolation level for the second one as “Snapshot” at the same time when we already start the transaction using BEGIN TRAN. -- Session 2 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that the values in the table are still original values. They have not been modified yet. Once again, go back to session 1 and begin the transaction. -- Session 1 COMMIT After that, go back to Session 2 and see the values of the table. -- Session 2 SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that the values are yet not changed and they are still the same old values which were there right in the beginning of the session. Now, let us commit the transaction in the session 2. Once committed, run the same SELECT statement once more and see what the result is. -- Session 2 COMMIT SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that it now reflects the new updated value. I hope that this example is clear enough as it would give you good idea how the Snapshot Isolation level works. There is much more to write about an extra level, READ_COMMITTED_SNAPSHOT, which we will be discussing in another post soon. If you wish to use this transaction’s Isolation level in your production database, I would appreciate your comments about their performance on your servers. I have included here the complete script used in this example for your quick reference. ALTER DATABASE AdventureWorks SET ALLOW_SNAPSHOT_ISOLATION ON GO SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 1 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN UPDATE HumanResources.Shift SET ModifiedDate = GETDATE() GO -- Session 2 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 1 COMMIT -- Session 2 SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 2 COMMIT SELECT ModifiedDate FROM HumanResources.Shift GO Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Transaction Isolation

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  • SQL SERVER – Simple Example of Snapshot Isolation – Reduce the Blocking Transactions

    - by pinaldave
    To learn any technology and move to a more advanced level, it is very important to understand the fundamentals of the subject first. Today, we will be talking about something which has been quite introduced a long time ago but not properly explored when it comes to the isolation level. Snapshot Isolation was introduced in SQL Server in 2005. However, the reality is that there are still many software shops which are using the SQL Server 2000, and therefore cannot be able to maintain the Snapshot Isolation. Many software shops have upgraded to the later version of the SQL Server, but their respective developers have not spend enough time to upgrade themselves with the latest technology. “It works!” is a very common answer of many when they are asked about utilizing the new technology, instead of backward compatibility commands. In one of the recent consultation project, I had same experience when developers have “heard about it” but have no idea about snapshot isolation. They were thinking it is the same as Snapshot Replication – which is plain wrong. This is the same demo I am including here which I have created for them. In Snapshot Isolation, the updated row versions for each transaction are maintained in TempDB. Once a transaction has begun, it ignores all the newer rows inserted or updated in the table. Let us examine this example which shows the simple demonstration. This transaction works on optimistic concurrency model. Since reading a certain transaction does not block writing transaction, it also does not block the reading transaction, which reduced the blocking. First, enable database to work with Snapshot Isolation. Additionally, check the existing values in the table from HumanResources.Shift. ALTER DATABASE AdventureWorks SET ALLOW_SNAPSHOT_ISOLATION ON GO SELECT ModifiedDate FROM HumanResources.Shift GO Now, we will need two different sessions to prove this example. First Session: Set Transaction level isolation to snapshot and begin the transaction. Update the column “ModifiedDate” to today’s date. -- Session 1 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN UPDATE HumanResources.Shift SET ModifiedDate = GETDATE() GO Please note that we have not yet been committed to the transaction. Now, open the second session and run the following “SELECT” statement. Then, check the values of the table. Please pay attention on setting the Isolation level for the second one as “Snapshot” at the same time when we already start the transaction using BEGIN TRAN. -- Session 2 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that the values in the table are still original values. They have not been modified yet. Once again, go back to session 1 and begin the transaction. -- Session 1 COMMIT After that, go back to Session 2 and see the values of the table. -- Session 2 SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that the values are yet not changed and they are still the same old values which were there right in the beginning of the session. Now, let us commit the transaction in the session 2. Once committed, run the same SELECT statement once more and see what the result is. -- Session 2 COMMIT SELECT ModifiedDate FROM HumanResources.Shift GO You will notice that it now reflects the new updated value. I hope that this example is clear enough as it would give you good idea how the Snapshot Isolation level works. There is much more to write about an extra level, READ_COMMITTED_SNAPSHOT, which we will be discussing in another post soon. If you wish to use this transaction’s Isolation level in your production database, I would appreciate your comments about their performance on your servers. I have included here the complete script used in this example for your quick reference. ALTER DATABASE AdventureWorks SET ALLOW_SNAPSHOT_ISOLATION ON GO SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 1 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN UPDATE HumanResources.Shift SET ModifiedDate = GETDATE() GO -- Session 2 SET TRANSACTION ISOLATION LEVEL SNAPSHOT BEGIN TRAN SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 1 COMMIT -- Session 2 SELECT ModifiedDate FROM HumanResources.Shift GO -- Session 2 COMMIT SELECT ModifiedDate FROM HumanResources.Shift GO Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Transaction Isolation

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  • Create a Shortcut to Put Your Windows Computer into Hibernation

    - by Mysticgeek
    Putting your Windows computer into Hibernation Mode allows you to save power, and quickly access your desktop again when you need it. Here we show how to create a shortcut to put your PC in Hibernation Mode quickly. Note: Here we show how to create the shortcut in Windows 7 and add it to the Taskbar. But creating the shortcut should work in XP and Vista as well. Create Shortcut  Right-click an empty area on your desktop and select New \ Shortcut from the Context Menu. In the Create Shortcut window type or copy the following in the location field… C:\Windows\System32\rundll32.exe powrprof.dll, SetSuspendState 0,1,0 Now give the shortcut a name such as Hibernate Computer or whatever you want to call it. Now you have the shortcut on your desktop, but you might want to change the icon to something else. Change Shortcut Icon Right-click the shortcut icon and select Properties. Select the Shortcut Tab and click the Change Icon button. In the Look for icons in this file field copy and past the following then click OK. %SystemRoot%\system32\SHELL32.dll This brings up a list of included Windows icons you can choose from. Select whatever you want it to be. There are a couple of Power icons in the directory…click OK. Of course you can choose any icon you want, if you customize your icons just browse to the directory they are in. For more on selecting icons check out our article on how to customize your icons in Windows 7 or how to change a file type’s icon. Now you will see the icon in the Shortcut Properties window, click OK. Here we have a nice looking shortcut that you can use to put your machine into Hibernation. Or here we used a customized Star Trek icon just to make things more interesting… You can pin the shortcut to the Taskbar for easy access. Conclusion If Hibernation is not enabled on your Windows 7 system you can easily manage it. By creating a shortcut and pinning to the Taskbar, it allows you to put your machine into Hibernation Mode quick and easy. If you like to customize your desktop with unique icons check out our posts on a Sci-Fi icon pack or Video Game icon pack. Similar Articles Productive Geek Tips Create a Shortcut for Locking Your Computer Screen in Windows 7 or VistaCreate Shutdown / Restart / Lock Icons in Windows 7 or VistaHow To Manage Hibernate Mode in Windows 7Microsoft Releases Pre-SP1 Updates for Windows VistaCreate a Shortcut or Hotkey to Run CCleaner Silently TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 10 Superb Firefox Wallpapers OpenDNS Guide Google TV The iPod Revolution Ultimate Boot CD can help when disaster strikes Windows Firewall with Advanced Security – How To Guides

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  • jQuery Selector Tester and Cheat Sheet

    - by SGWellens
    I've always appreciated these tools: Expresso and XPath Builder. They make designing regular expressions and XPath selectors almost fun! Did I say fun? I meant less painful. Being able to paste/load text and then interactively play with the search criteria is infinitely better than the code/compile/run/test cycle. It's faster and you get a much better feel for how the expressions work. So, I decided to make my own interactive tool to test jQuery selectors:  jQuery Selector Tester.   Here's a sneak peek: Note: There are some existing tools you may like better: http://www.woods.iki.fi/interactive-jquery-tester.html http://www.w3schools.com/jquery/trysel.asp?filename=trysel_basic&jqsel=p.intro,%23choose My tool is different: It is one page. You can save it and run it locally without a Web Server. It shows the results as a list of iterated objects instead of highlighted html. A cheat sheet is on the same page as the tester which is handy. I couldn't upload an .htm or .html file to this site so I hosted it on my personal site here: jQuery Selector Tester. Design Highlights: To make the interactive search work, I added a hidden div to the page: <!--Hidden div holds DOM elements for jQuery to search--><div id="HiddenDiv" style="display: none"></div> When ready to search, the searchable html text is copied into the hidden div…this renders the DOM tree in the hidden div: // get the html to search, insert it to the hidden divvar Html = $("#TextAreaHTML").val();$("#HiddenDiv").html(Html); When doing a search, I modify the search pattern to look only in the HiddenDiv. To do that, I put a space between the patterns.  The space is the Ancestor operator (see the Cheat Sheet): // modify search string to only search in our// hidden div and do the searchvar SearchString = "#HiddenDiv " + SearchPattern;try{    var $FoundItems = $(SearchString);}   Big Fat Stinking Faux Pas: I was about to publish this article when I made a big mistake: I tested the tool with Mozilla FireFox. It blowed up…it blowed up real good. In the past I’ve only had to target IE so this was quite a revelation. When I started to learn JavaScript, I was disgusted to see all the browser dependent code. Who wants to spend their time testing against different browsers and versions of browsers? Adding a bunch of ‘if-else’ code is a tedious and thankless task. I avoided client code as much as I could. Then jQuery came along and all was good. It was browser independent and freed us from the tedium of worrying about version N of the Acme browser. Right? Wrong! I had used outerHTML to display the selected elements. The problem is Mozilla FireFox doesn’t implement outerHTML. I replaced this: // encode the html markupvar OuterHtml = $('<div/>').text(this.outerHTML).html(); With this: // encode the html markupvar Html = $('<div>').append(this).html();var OuterHtml = $('<div/>').text(Html).html(); Another problem was that Mozilla FireFox doesn’t implement srcElement. I replaced this: var Row = e.srcElement.parentNode;  With this: var Row = e.target.parentNode; Another problem was the indexing. The browsers have different ways of indexing. I replaced this: // this cell has the search pattern  var Cell = Row.childNodes[1];   // put the pattern in the search box and search                    $("#TextSearchPattern").val(Cell.innerText);  With this: // get the correct cell and the text in the cell// place the text in the seach box and serachvar Cell = $(Row).find("TD:nth-child(2)");var CellText = Cell.text();$("#TextSearchPattern").val(CellText);   So much for the myth of browser independence. Was I overly optimistic and gullible? I don’t think so. And when I get my millions from the deposed Nigerian prince I sent money to, you’ll see that having faith is not futile. Notes: My goal was to have a single standalone file. I tried to keep the features and CSS to a minimum–adding only enough to make it useful and visually pleasing. When testing, I often thought there was a problem with the jQuery selector. Invariable it was invalid html code. If your results aren't what you expect, don't assume it's the jQuery selector pattern: The html may be invalid. To help in development and testing, I added a double-click handler to the rows in the Cheat Sheet table. If you double-click a row, the search pattern is put in the search box, a search is performed and the page is scrolled so you can see the results. I left the test html and code in the page. If you are using a CDN (non-local) version of the jQuery libraray, the designer in Visual Studio becomes extremely slow.  That's why there are two version of the library in the header and one is commented out. For reference, here is the jQuery documentation on selectors: http://api.jquery.com/category/selectors/ Here is a much more comprehensive list of CSS selectors (which jQuery uses): http://www.w3.org/TR/CSS2/selector.html I hope someone finds this useful. Steve WellensCodeProject

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  • Rights Expiry Options in IRM 11g

    - by martin.abrahams
    Among the many enhancements in IRM 11g, we have introduced a couple of new rights expiry options that may be applied to any role. These options were supported in previous versions, but fell into the "advanced configuration" category. In 11g, the options can be applied simply by selecting a check-box in the properties of a role, as shown by the rather extreme example below, where the role allows access for just two minutes after they are sealed. The new options are: To define a role that expires automatically some period after it is assigned To define a role that evaluates expiry relative to the time that each document is sealed These options supplement the familiar options to allow open-ended access (limited by offline access and the ever-present option to revoke rights at any time) and the option to define time windows with specific start dates and end dates. The value of these options is easiest to illustrate with some publishing examples: You might define a role with a one year expiry to be assigned to users who purchase a one year subscription. For each individual user, the year would be calculated from the time that the role was assigned to them. You might define a role that allows documents to be accessed only for 24 hours from the time that they are published - perhaps as a preview mechanism designed to tempt users to sign up for a full subscription. Upon payment of a full fee, users can simply be reassigned a role that gives them greater access to exactly the same documents. In a corporate environment, you might use such roles for fixed term contractors or for workflows that involve information with a short lifespan, or perhaps as part of a compliance process that requires rights to be formally re-approved at intervals. Being role-based, the time constraints apply to any number of documents - including documents that have not yet been created. For example, a user with a one year subscription would have access to all documents published in the relevant classification during the year without any further configuration. Crucially, unlike other solutions, it is not the documents that expire, but the rights of particular users. Whereas some solutions make documents completely inaccessible for all users after expiry, Oracle IRM can allow some users to continue using documents while other users lose access. Equally crucially, a user whose rights have expired can always be granted fresh rights at any time - for example, because they renew their subscription or because a manager confirms that they still need the rights as part of a corporate compliance process. By applying expiry to rights rather than to documents, Oracle IRM avoids the risk of locking an organization out of its own information.

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  • Reset All Internet Explorer 8 Settings to Fix Stability Problems

    - by Mysticgeek
    If you like to tweak and customize IE with Add-ons and changing settings, sometimes you may have problems with stability. To save time, you can reset all of the IE settings rather than trying to troubleshoot individual areas. Reset IE Settings To reset Internet Explorer Settings, click on Tools then Internet Options. When you reset the settings, you won’t lose personal settings like your homepage, search provider, passwords…etc. The Internet Options screen opens…click on the Advanced tab, then under Reset Internet Explorer settings click on the Reset button. You’ll need to verify that you want to reset all Internet Explorer Settings. If you choose to, you can delete all of your personal settings as well, but it shouldn’t be necessary to fix stability issues. The settings will start to reset, and when it’s finished close out of the message box. For the process to complete you’ll need to restart Internet Explorer. When it restarts you’ll be presented with the Welcome screen where you can go through the setup wizard again. After it’s complete, you should be back in business and can start using IE again. With the new enhancements and features available in Internet Explorer 8, sometimes too much tweaking can cause it to stop working. One area you could start with is troubleshooting IE 8 Add-ons. However, if you don’t want to waste time troubleshooting each potential issue, sometimes it’s just easier to reset things back to how they were originally. Similar Articles Productive Geek Tips Troubleshooting Internet Explorer on Vista Locking Up or Running SlowlyFix Internet Explorer Not Prompting to Choose Save Location in XPDealing With Windows Vista Explorer Screwing Up Auto-Detection of Folder TypesMysticgeek Blog: A Look at Internet Explorer 8 Beta 1 on Windows XPClean Up Past Notification Icons in Windows Vista TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Gadfly is a cool Twitter/Silverlight app Enable DreamScene in Windows 7 Microsoft’s “How Do I ?” Videos Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow

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  • Red Gate does Byte Night 2012

    - by red(at)work
    On the 5th of October 2012, a team of nine plucky Red Gaters braved the howling wind and the driving rain to sleep outside. No tents or mattresses were allowed – all we took for protection were sleeping bags, groundsheets, plastic sacks and Colin’s enormous fishing umbrella (a godsend in umbrella-y disguise). Why would we do such a thing? For Byte Night, an annual tech sector sleepout in support of Action for Children, who tackle the causes as well as the consequences of youth homelessness. Byte Night encourages technology professionals to do for one night a year what thousands of young people have to do every night – sleep rough.  We signed up for Byte Night in the warm, heady midst of the British summer, thinking it couldn’t possibly be all that bad. Even on the night itself – before the rain began to fall, sat in the comfort and warmth of a company canteen, drinking wine and eating chill and preparing to win the pub quiz – we were excited and optimistic about the night that lay ahead of us. All of that changed as soon as we stepped out into one of the worst rainstorms of the year. Brian, the team’s birthday boy, describes it best: Picture the scene: it’s 3 am on a Friday. I’m lying outside, fully clothed in a sleeping bag, wearing a raincoat, trussed up inside a large plastic pocket, on a ground sheet beneath a giant umbrella, wedged so tightly between two of my colleagues that I can’t move my arms. I’m wide awake, staring up at the grey sky beyond the edge of the umbrella; a limp, flickering white glow hints at a moon somewhere behind the drifting clouds. I haven’t slept since we first moved outside at 11 pm. Outside. Did I mention we were outside? I’m hung over. I need the loo. But there is no way on earth that I’m getting out of this sleeping bag. It’s cold. It’s raining. Not just raining, but chucking it down. It’s been doing this non-stop since 10pm. The rain sounds like a hyperactive drummer on the fishing umbrella, and the noise is loud and relentless. Puddles of water are forming all over the groundsheet, and, despite being ensconced inside the plastic pouch, I am wet. The fishing umbrella is protecting me from the worst of the driving rain, but not all of me is under it, and five hours of rain is no match for it. Everything is wet. My left side has become horribly damp. My trainers, which I placed next to my sleeping bag, are now completely soaked through. Mmm. That’ll be fun in the morning. My head is next to Colin’s head on one side, and a multi-pack of McCoy’s cheddar and onion crisps on the other. Don’t ask about the tub of hummus. That’s somewhere down by my ankles, abandoned to the night. Jess, who is lying next to me, rolls over onto her side. A mini waterfall cascades from her rain-pouch onto my face. Bah. I continue to stare into the heavens, willing the dawn to hurry up. Something lands on my face. It’s a mosquito. Great. Midnight, when this still seemed like fun – when we opened some champagne and my colleagues presented me with a caterpillar birthday cake, when everyone was drunk and jolly and full of stoic resolve – feels like a long time ago. Did I mention that today is my birthday? The remains of the caterpillar cake endure the same fate as the hummus, left out in the rain like a metaphor for sadness. It’s getting colder. I can see my breath. Silence has descended on the group, apart from the rustle of plastic. And the rain, obviously. Someone snores, and I envy whoever it is the sweet escape of sleep. I try to wriggle a bit further down inside my sleeping bag, but it doesn’t want to be wriggled into. Only 3 hours till dawn. 180 minutes. I begin to count them off, one at a time.  All nine of us got to go home in the morning, but thousands of children across the UK don’t have that luxury. If you’d like to sponsor the Red Gate Byte Night team, our JustGiving page can be found here.   Chris, before the outside bit actually happened. More photos from Byte Night Cambridge 2012 can be found here.

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  • July, the 31 Days of SQL Server DMO’s – Day 24 (sys.dm_db_index_operational_stats)

    - by Tamarick Hill
    The sys.dm_db_index_operational_stats Dynamic Management Function returns information about the IO, locking, and access methods for the indexes that you currently have on your SQL Server Instance. This function takes four input parameters which are (1) database_id, (2) object_id, (3) index_id, and (4) partition_number. Let’s have a look at the results from this function against our AdventureWorks2012 database. This function returns a ton of columns, so not only will I not attempt to describe each of the columns, I wont even attempt to display all of them here. My query below will give you a subset of the columns returned from this function. SELECT database_id, object_id, index_id, partition_number, leaf_insert_count, leaf_delete_count, leaf_update_count, leaf_ghost_count, nonleaf_insert_count, nonleaf_delete_count, nonleaf_update_count, range_scan_count, forwarded_fetch_count, row_lock_count, row_lock_wait_count, page_lock_count, page_lock_wait_count, Index_lock_promotion_attempt_count, index_lock_promotion_count, page_compression_attempt_count, page_compression_success_count FROM sys.dm_db_index_operational_stats(db_id('AdventureWorks2012'), NULL, NULL, NULL) The first four columns in the result set represent the values that we passed in as our input parameters. If you use NULL’s as I did, then you will see results for every index on your system. I specified a database_id so my result set only shows those records pertaining to my AdventureWorks2012 database. The next columns in the result set provide you with information on how may inserts, deletes, or updates that have taken place on your leaf and nonleaf index levels. The nonleaf levels would refer to the intermediate and root index levels. In the middle of these you see a leaf_ghost_count column, which represents the number of records that have been logically deleted and marked as “ghosted”  and are waiting on the background ghost cleanup process to physically remove them. The range_scan_count column represents the number of range or table scans that have been performed against an index. The forwarded_fetch_count column represents the number of rows that were returned from a forwarding row pointer. The row_lock_count and row_lock_wait_count represent the number of row locks that have been requested for an index and the number of times SQL has had to wait on a row lock respectively. The page_lock_count and page_lock_wait_count represent the number of page locks that have been requested for an index and the number of times SQL has had to wait on a page lock respectively. The index_lock_promotion_attempt_count represents the number of times the database engine has attempted to promote a lock to the index level. The index_lock_promotion_count column displays how many times that index lock promotion was successful. Lastly the page_compression_attempt_count and page_compression_success_count represents how many times a page was attempted to be compressed and how many times the attempt was successful. As you can see there is a ton of information returned from this DMV. The DMV we reviewed on yesterday (sys.dm_db_index_usage_stats) provided you with good information on when and how indexes have been used, but this DMF takes an even deeper dive into these statistics. If you are interested in performing a very detailed analysis on the operational stats of your indexes, this is not only a good place to start, but more than likely the best place. For more information on this Dynamic Management Function, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms174281.aspx Follow me on Twitter @PrimeTimeDBA

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  • SQL SERVER – Sharing your ETL Resources Across Applications with Ease

    - by pinaldave
    Frequently an organization will find that the same resources are used in multiple ETL applications, for example, the same database, general purpose processing logic, or file system locations.  Creating an easy way to reuse these resources across multiple applications would increase efficiency and reduce errors.  Moreover, not every ETL developer has the same skill set, and it is likely that one developer will be more adept at writing code while another is more comfortable configuring database connections.  Real productivity gains will come when these developers are able to work independently while still making their work available to others assigned to the same project.  These are the benefits of a centralized version control system. Of course, most version control systems could be used to store and serve files, but the real need is to store and serve entire ETL applications so that each developer’s ongoing work can immediately benefit from another developer’s completed work.  In other words, the version control system needs to be tightly integrated with the tools used to develop the ETL application. The following screen shot shows such a tool. Desktop ETL tool that tightly integrates with a central version control system Developers can checkout or commit entire projects or just a single artifact.  Each artifact may be managed independently so if you need to go back to an earlier version of one artifact, changes you may have made to other artifacts are not lost.  By being tightly integrated into the graphical environment used to create and edit the project artifacts, it is extremely easy and straight-forward to move your files to and from the version control system and there is no dependency on another vendor’s version control system.  The built in version control system is optimized for managing the artifacts of ETL applications. It is equally important that the version control system supports all of the actions one typically performs such as rollbacks, locking and unlocking of files, and the ability to resolve conflicts.  Note that this particular ETL tool also has the capability to switch back and forth between multiple version control systems. It also needs to be easy to determine the status of an artifact.  Not just that it has been committed or modified, but when and by whom.  Generally you must query the version control system for this information, but having it displayed within the development environment is more desirable. Who’s ETL tool works in this fashion?  Last month I mentioned the data integration solution offered by expressor software.  The version control features I described in this post are all available in their just released expressor 3.1 Standard Edition through the integration of their expressor Studio development environment with a centralized metadata repository and version control system. You can download their Studio application, which is free, or evaluate the full Standard Edition on your own hardware.  It may be worth your time. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Goodbye XML&hellip; Hello YAML (part 2)

    - by Brian Genisio's House Of Bilz
    Part 1 After I explained my motivation for using YAML instead of XML for my data, I got a lot of people asking me what type of tooling is available in the .Net space for consuming YAML.  In this post, I will discuss a nice tooling option as well as describe some small modifications to leverage the extremely powerful dynamic capabilities of C# 4.0.  I will be referring to the following YAML file throughout this post Recipe: Title: Macaroni and Cheese Description: My favorite comfort food. Author: Brian Genisio TimeToPrepare: 30 Minutes Ingredients: - Name: Cheese Quantity: 3 Units: cups - Name: Macaroni Quantity: 16 Units: oz Steps: - Number: 1 Description: Cook the macaroni - Number: 2 Description: Melt the cheese - Number: 3 Description: Mix the cooked macaroni with the melted cheese Tooling It turns out that there are several implementations of YAML tools out there.  The neatest one, in my opinion, is YAML for .NET, Visual Studio and Powershell.  It includes a great editor plug-in for Visual Studio as well as YamlCore, which is a parsing engine for .Net.  It is in active development still, but it is certainly enough to get you going with YAML in .Net.  Start by referenceing YamlCore.dll, load your document, and you are on your way.  Here is an example of using the parser to get the title of the Recipe: var yaml = YamlLanguage.FileTo("Data.yaml") as Hashtable; var recipe = yaml["Recipe"] as Hashtable; var title = recipe["Title"] as string; In a similar way, you can access data in the Ingredients set: var yaml = YamlLanguage.FileTo("Data.yaml") as Hashtable; var recipe = yaml["Recipe"] as Hashtable; var ingredients = recipe["Ingredients"] as ArrayList; foreach (Hashtable ingredient in ingredients) { var name = ingredient["Name"] as string; } You may have noticed that YamlCore uses non-generic Hashtables and ArrayLists.  This is because YamlCore was designed to work in all .Net versions, including 1.0.  Everything in the parsed tree is one of two things: Hashtable, ArrayList or Value type (usually String).  This translates well to the YAML structure where everything is either a Map, a Set or a Value.  Taking it further Personally, I really dislike writing code like this.  Years ago, I promised myself to never write the words Hashtable or ArrayList in my .Net code again.  They are ugly, mostly depreciated collections that existed before we got generics in C# 2.0.  Now, especially that we have dynamic capabilities in C# 4.0, we can do a lot better than this.  With a relatively small amount of code, you can wrap the Hashtables and Array lists with a dynamic wrapper (wrapper code at the bottom of this post).  The same code can be re-written to look like this: dynamic doc = YamlDoc.Load("Data.yaml"); var title = doc.Recipe.Title; And dynamic doc = YamlDoc.Load("Data.yaml"); foreach (dynamic ingredient in doc.Recipe.Ingredients) { var name = ingredient.Name; } I significantly prefer this code over the previous.  That’s not all… the magic really happens when we take this concept into WPF.  With a single line of code, you can bind to the data dynamically in the view: DataContext = YamlDoc.Load("Data.yaml"); Then, your XAML is extremely straight-forward (Nothing else.  No static types, no adapter code.  Nothing): <StackPanel> <TextBlock Text="{Binding Recipe.Title}" /> <TextBlock Text="{Binding Recipe.Description}" /> <TextBlock Text="{Binding Recipe.Author}" /> <TextBlock Text="{Binding Recipe.TimeToPrepare}" /> <TextBlock Text="Ingredients:" FontWeight="Bold" /> <ItemsControl ItemsSource="{Binding Recipe.Ingredients}" Margin="10,0,0,0"> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding Quantity}" /> <TextBlock Text=" " /> <TextBlock Text="{Binding Units}" /> <TextBlock Text=" of " /> <TextBlock Text="{Binding Name}" /> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> <TextBlock Text="Steps:" FontWeight="Bold" /> <ItemsControl ItemsSource="{Binding Recipe.Steps}" Margin="10,0,0,0"> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding Number}" /> <TextBlock Text=": " /> <TextBlock Text="{Binding Description}" /> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </StackPanel> This nifty XAML binding trick only works in WPF, unfortunately.  Silverlight handles binding differently, so they don’t support binding to dynamic objects as of late (March 2010).  This, in my opinion, is a major lacking feature in Silverlight and I really hope we will see this feature available to us in Silverlight 4 Release.  (I am not very optimistic for Silverlight 4, but I can hope for the feature in Silverlight 5, can’t I?) Conclusion I still have a few things I want to say about using YAML in the .Net space including de-serialization and using IronRuby for your YAML parser, but this post is hopefully enough to see how easy it is to incorporate YAML documents in your code. Codeplex Site for YAML tools Dynamic wrapper for YamlCore

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  • Responsible BI for Excel, Even for Older Versions

    - by andrewbrust
    On Wednesday, I will have the honor of co-presenting, for both The Data Warehouse Institute (TDWI) and the New York Technology Council. on the subject of Excel and BI. My co-presenter will be none other than Bill Baker, who was a Microsoft Distinguished Engineer and, essentially, the father of BI at that company.  Details on the events are here and here. We'll be talking about PowerPivot, of course, but that's not all. Probably even more important than any one product, will be our discussion of whether the usual characterization of Excel as the nemesis of IT, the guilty pleasure of business users and the antithesis of formal BI is really valid and/or hopelessly intractable. Without giving away our punchline, I'll tell you that we are much more optimistic than that. There are huge upsides to Excel and while there are real dangers to using it in the BI space, there are standards and practices you can employ to ensure Excel is used responsibly. And when those practices are followed, Excel becomes quite powerful indeed. One of the keys to this is using Excel as a data consumer rather than data storage mechanism. Caching data in Excel is OK, but only if that data is (a) not modified and (b) configured for automated periodic refresh. PowerPivot meets both criteria -- it stores a read-only copy of your data in the form of a model, and once workbook containing a PowerPivot model is published to SharePoint, it can be configured for scheduled data refresh, on the server, requiring no user intervention whatsoever. Data refresh is a bit like hard drive backup: it will only happen reliably if it's automated, and super-easy to configure. PowerPivot hits a real home run here (as does Windows Home Server for PC backup, but I digress). The thing about PowerPivot is that it's an add-in for Excel 2010. What if you're not planning to go to that new version for quite a while? What if you’ve just deployed Office 2007 in your organization? What if you're still on Office 2003, or an even earlier version? What can you do immediately to share data responsibly and easily? As it turns out, there's a feature in Excel that's been around for quite a while, that can help: Web Queries.  The Web Query feature was introduced, ostensibly, to allow Excel to pull data in from Internet Web pages…for example, data in a stock quote history table will come in nicely, as will any data in a Web page that is displayed in an HTML table.  To use the feature In Excel 2007 or 2010, click the Data Tab or the ribbon and click the “From Web” button towards the left; in older versions use the corresponding option in  the menu or  toolbars.  Next, paste a URL into the resulting dialog box and tap Enter or click the Go button.  A preview of the Web page will come up, and the dialog will allow you to select the specific table within the page whose data you’d like to import.  Here’s an example: Now just click the table, click the Import button, and the Import Data dialog appears.  You can simply click OK to bring in your data or you can first click the Properties… button and configure the data import to be refreshed at an interval in minutes that you select.  Now your data’s in the spreadsheet and ready to worked with: Your data may be vulnerable to modification, but if you’ve set up the data refresh, any accidental or malicious changes will be corrected in time anyway. The thing about this feature is that it’s most useful not for public Web pages, but for pages behind the firewall.  In effect, the Web Query feature provides an incredibly easy way to consume data in Excel that’s “published” from an application.  Users just need a URL.  They don’t need to know server and database names and since the data is read-only, providing credentials may be unnecessary, or can be handled using integrated security.  If that’s not good enough, the Web Query can be saved to a special .iqy file, which can be edited to provide POST parameter data. The only requirement is that the data must be provided in an HTML table, with the first row providing the column names.  From an ASP.NET project, it couldn’t be easier: a simple bound GridView control is totally compatible.  Use a data source control with it, and you don’t even have to write any code.  Users can link to pages that are part of an application’s UI, or developers can create pages that are specially designed for the purpose of providing an interface to the Web Query import feature.  And none of this is Microsoft- or .NET-specific.  You can create pages in any language you want (PHP comes to mind) that output the result set of a query in HTML table format, and then consume that data in a Web Query.  Then build PivotTables and charts on the data, and in Excel 2007 or 2010 you can use conditional formatting to create scorecards and dashboards. This strategy allows you to create pages that function quite similarly to the OData XML feeds rendered when .NET developers create an “Astoria” WCF Data Service.  And while it’s cool that PowerPivot and Excel 2010 can import such OData feeds, it’s good to know that older versions of Excel can function in a similar fashion, and can consume data produced by virtually any Web development platform. As a final matter, instead of just telling you that “older versions” of Excel support this feature, I’ll be more specific.  To discover what the first version of Excel was to support Web queries, go to http://bit.ly/OldSchoolXL.

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  • Inverted schedctl usage in the JVM

    - by Dave
    The schedctl facility in Solaris allows a thread to request that the kernel defer involuntary preemption for a brief period. The mechanism is strictly advisory - the kernel can opt to ignore the request. Schedctl is typically used to bracket lock critical sections. That, in turn, can avoid convoying -- threads piling up on a critical section behind a preempted lock-holder -- and other lock-related performance pathologies. If you're interested see the man pages for schedctl_start() and schedctl_stop() and the schedctl.h include file. The implementation is very efficient. schedctl_start(), which asks that preemption be deferred, simply stores into a thread-specific structure -- the schedctl block -- that the kernel maps into user-space. Similarly, schedctl_stop() clears the flag set by schedctl_stop() and then checks a "preemption pending" flag in the block. Normally, this will be false, but if set schedctl_stop() will yield to politely grant the CPU to other threads. Note that you can't abuse this facility for long-term preemption avoidance as the deferral is brief. If your thread exceeds the grace period the kernel will preempt it and transiently degrade its effective scheduling priority. Further reading : US05937187 and various papers by Andy Tucker. We'll now switch topics to the implementation of the "synchronized" locking construct in the HotSpot JVM. If a lock is contended then on multiprocessor systems we'll spin briefly to try to avoid context switching. Context switching is wasted work and inflicts various cache and TLB penalties on the threads involved. If context switching were "free" then we'd never spin to avoid switching, but that's not the case. We use an adaptive spin-then-park strategy. One potentially undesirable outcome is that we can be preempted while spinning. When our spinning thread is finally rescheduled the lock may or may not be available. If not, we'll spin and then potentially park (block) again, thus suffering a 2nd context switch. Recall that the reason we spin is to avoid context switching. To avoid this scenario I've found it useful to enable schedctl to request deferral while spinning. But while spinning I've arranged for the code to periodically check or poll the "preemption pending" flag. If that's found set we simply abandon our spinning attempt and park immediately. This avoids the double context-switch scenario above. One annoyance is that the schedctl blocks for the threads in a given process are tightly packed on special pages mapped from kernel space into user-land. As such, writes to the schedctl blocks can cause false sharing on other adjacent blocks. Hopefully the kernel folks will make changes to avoid this by padding and aligning the blocks to ensure that one cache line underlies at most one schedctl block at any one time.

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  • Surface and the Uphill Battle to Win Over iPad Users (Namely: Me)

    - by D'Arcy Lussier
    I went away this past weekend and decided to bring along the Windows 8 tablet from the Build conference last year – y’know, to give Windows 8 a try in a typical scenario. I also brought our iPad 2 along since I figured my wife would want to use that. I’d love to tell you how I found using my Windows 8 tablet but I can’t – I used the iPad exclusively the entire weekend. It was during this that I realized what Microsoft needs to do to win me over as an iPad user. As you’ll see, I’m left wondering what it is that Surface is meant to compete with: iPad and other tablets, or thin laptops like the MacBook Air or Ultrabooks. Device Size I really like the size of the iPad compared with the Build tablet. It’s not as long and the thinness/weight of the device makes it feel more like you’re holding a magazine than a computer. I’m pleased that Microsoft will be matching the thinness of the iPad with Surface, but I’m suspect as to what that actually means. The iPad’s edges slant inwards where the Surface has a thicker boxish look (similar to the iPhone 4S). So while they may have the same depth at the deepest part of both devices, I bet the iPad will come off feeling thinner. However, its not lost on me the number of external port options the Surface’s design provides over the iPad (Usb, etc.). With that said, I haven’t missed having a USB slot on my iPad. I’m not a fan of lengthening the Surface screen size to almost a full inch over the iPad, mainly because… Vertical Orientation Experience Did you notice at the announce event, in the images of the devices that have been released, and in any marketing for it, that the surface is always displayed in horizontal orientation. This is a huge beef I have with my Build tablet and why I prefer the iPad. Yes the iPad can do the wide-screenish mode, but the iPad is oriented to be vertical by nature. Don’t agree? Look at the button and camera placement – both on the shorter sides of the device. Compare that with the Surface, where the orientation for the button and camera is on the longer sides. To be fair, Blackberry and the horde of Android tablets out there haven’t gotten this either – since most monitors are widescreen nowadays tablets should be too right? Wrong. Widescreen is great for certain things, but tasks such as reading is not one of them – hence why monitor companies like Dell provide stands that allow you to flip your widescreen monitor to a vertical orientation. That Microsoft has chosen a horizontal orientation by default for Windows 8 is disappointing – hopefully hardware manufacturers will be given the option of a default vertical orientation. Fast Startup Time I like that I can turn off/turn on the iPad very quickly. Even from a true “off” mode and not just sleeping, the iPad boots up very quickly. Windows RT needs to have that same quick response. If I start finding that I’m waiting for the device to boot up for more than 30 seconds that could be a show stopper. No Heat I really hate that the Build tablet has fans that kick in to cool the procs, but its basically a slate computer and I get its part of that prototype build. For Surface, it needs to be the same type of experience as the iPad – no heat! I know Surface doesn’t have fans and uses some cool new vent system or something like that, but even then – I want to sit and read a book on my Surface without having to feel any heat coming from the device, which is the experience I have with the iPad now. What About Apps?! I am definitely not the target client when it comes to app stores. On my iPad I use: Safari Kindle Reader Twitter App Settlers of Catan TSN’s App And that’s it. So really, while its nice that some version of Office might be available, I’m not planning on utilizing a Surface for creating a PowerPoint or working on a Word document – that’s what my laptop is for. I want my tablet to be for information snacking or as an e-reader and occasionally an entertainment device. Surface vs iPad or Surface vs Air? The more that I read up on Surface, the more I wonder if it won’t be a touch-enabled MacBook Air competitor more than an iPad one. Also, I really question if Microsoft gets tablets – when one of your main selling features is a built-in physical keyboard it speaks more to a traditional laptop experience than a tablet one that’s entirely reliant on touch. Still, I really love the Windows Phone interface – way more than iOS – so I’m still very optimistic that the Metro experience on the tablet will be fantastic. I just worry that Microsoft has interpreted a tablet as a computer with a removable keyboard and a touch screen, and that’s not what tablet computing is about at all.

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  • Why lock statements don't scale

    - by Alex.Davies
    We are going to have to stop using lock statements one day. Just like we had to stop using goto statements. The problem is similar, they're pretty easy to follow in small programs, but code with locks isn't composable. That means that small pieces of program that work in isolation can't necessarily be put together and work together. Of course actors scale fine :) Why lock statements don't scale as software gets bigger Deadlocks. You have a program with lots of threads picking up lots of locks. You already know that if two of your threads both try to pick up a lock that the other already has, they will deadlock. Your program will come to a grinding halt, and there will be fire and brimstone. "Easy!" you say, "Just make sure all the threads pick up the locks in the same order." Yes, that works. But you've broken composability. Now, to add a new lock to your code, you have to consider all the other locks already in your code and check that they are taken in the right order. Algorithm buffs will have noticed this approach means it takes quadratic time to write a program. That's bad. Why lock statements don't scale as hardware gets bigger Memory bus contention There's another headache, one that most programmers don't usually need to think about, but is going to bite us in a big way in a few years. Locking needs exclusive use of the entire system's memory bus while taking out the lock. That's not too bad for a single or dual-core system, but already for quad-core systems it's a pretty large overhead. Have a look at this blog about the .NET 4 ThreadPool for some numbers and a weird analogy (see the author's comment). Not too bad yet, but I'm scared my 1000 core machine of the future is going to go slower than my machine today! I don't know the answer to this problem yet. Maybe some kind of per-core work queue system with hierarchical work stealing. Definitely hardware support. But what I do know is that using locks specifically prevents any solution to this. We should be abstracting our code away from the details of locks as soon as possible, so we can swap in whatever solution arrives when it does. NAct uses locks at the moment. But my advice is that you code using actors (which do scale well as software gets bigger). And when there's a better way of implementing actors that'll scale well as hardware gets bigger, only NAct needs to work out how to use it, and your program will go fast on it's own.

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