Search Results

Search found 2100 results on 84 pages for 'somewhat offtopic'.

Page 75/84 | < Previous Page | 71 72 73 74 75 76 77 78 79 80 81 82  | Next Page >

• MERGE gives better OUTPUT options

  - by Rob Farley

  MERGE is very cool. There are a ton of useful things about it – mostly around the fact that you can implement a ton of change against a table all at once. This is great for data warehousing, handling changes made to relational databases by applications, all kinds of things. One of the more subtle things about MERGE is the power of the OUTPUT clause. Useful for logging.   If you’re not familiar with the OUTPUT clause, you really should be – it basically makes your DML (INSERT/DELETE/UPDATE/MERGE) statement return data back to you. This is a great way of returning identity values from INSERT commands (so much better than SCOPE_IDENTITY() or the older (and worse) @@IDENTITY, because you can get lots of rows back). You can even use it to grab default values that are set using non-deterministic functions like NEWID() – things you couldn’t normally get back without running another query (or with a trigger, I guess, but that’s not pretty). That inserted table I referenced – that’s part of the ‘behind-the-scenes’ work that goes on with all DML changes. When you insert data, this internal table called inserted gets populated with rows, and then used to inflict the appropriate inserts on the various structures that store data (HoBTs – the Heaps or B-Trees used to store data as tables and indexes). When deleting, the deleted table gets populated. Updates get a matching row in both tables (although this doesn’t mean that an update is a delete followed by an inserted, it’s just the way it’s handled with these tables). These tables can be referenced by the OUTPUT clause, which can show you the before and after for any DML statement. Useful stuff. MERGE is slightly different though. With MERGE, you get a mix of entries. Your MERGE statement might be doing some INSERTs, some UPDATEs and some DELETEs. One of the most common examples of MERGE is to perform an UPSERT command, where data is updated if it already exists, or inserted if it’s new. And in a single operation too. Here, you can see the usefulness of the deleted and inserted tables, which clearly reflect the type of operation (but then again, MERGE lets you use an extra column called $action to show this). (Don’t worry about the fact that I turned on IDENTITY_INSERT, that’s just so that I could insert the values) One of the things I love about MERGE is that it feels almost cursor-like – the UPDATE bit feels like “WHERE CURRENT OF …”, and the INSERT bit feels like a single-row insert. And it is – but into the inserted and deleted tables. The operations to maintain the HoBTs are still done using the whole set of changes, which is very cool. And $action – very convenient. But as cool as $action is, that’s not the point of my post. If it were, I hope you’d all be disappointed, as you can’t really go near the MERGE statement without learning about it. The subtle thing that I love about MERGE with OUTPUT is that you can hook into more than just inserted and deleted. Did you notice in my earlier query that my source table had a ‘src’ field, that wasn’t used in the insert? Normally, this would be somewhat pointless to include in my source query. But with MERGE, I can put that in the OUTPUT clause. This is useful stuff, particularly when you’re needing to audit the changes. Suppose your query involved consolidating data from a number of sources, but you didn’t need to insert that into the actual table, just into a table for audit. This is now very doable, either using the INTO clause of OUTPUT, or surrounding the whole MERGE statement in brackets (parentheses if you’re American) and using a regular INSERT statement. This is also doable if you’re using MERGE to just do INSERTs. In case you hadn’t realised, you can use MERGE in place of an INSERT statement. It’s just like the UPSERT-style statement we’ve just seen, except that we want nothing to match. That’s easy to do, we just use ON 1=2. This is obviously more convoluted than a straight INSERT. And it’s slightly more effort for the database engine too. But, if you want the extra audit capabilities, the ability to hook into the other source columns is definitely useful. Oh, and before people ask if you can also hook into the target table’s columns... Yes, of course. That’s what deleted and inserted give you.

  Read the article

• Annoying flickering of vertices and edges (possible z-fighting)

  - by Belgin

  I'm trying to make a software z-buffer implementation, however, after I generate the z-buffer and proceed with the vertex culling, I get pretty severe discrepancies between the vertex depth and the depth of the buffer at their projected coordinates on the screen (i.e. zbuffer[v.xp][v.yp] != v.z, where xp and yp are the projected x and y coordinates of the vertex v), sometimes by a small fraction of a unit and sometimes by 2 or 3 units. Here's what I think is happening: Each triangle's data structure holds the plane's (that is defined by the triangle) coefficients (a, b, c, d) computed from its three vertices from their normal: void computeNormal(Vertex *v1, Vertex *v2, Vertex *v3, double *a, double *b, double *c) { double a1 = v1 -> x - v2 -> x; double a2 = v1 -> y - v2 -> y; double a3 = v1 -> z - v2 -> z; double b1 = v3 -> x - v2 -> x; double b2 = v3 -> y - v2 -> y; double b3 = v3 -> z - v2 -> z; *a = a2*b3 - a3*b2; *b = -(a1*b3 - a3*b1); *c = a1*b2 - a2*b1; } void computePlane(Poly *p) { double x = p -> verts[0] -> x; double y = p -> verts[0] -> y; double z = p -> verts[0] -> z; computeNormal(p -> verts[0], p -> verts[1], p -> verts[2], &p -> a, &p -> b, &p -> c); p -> d = p -> a * x + p -> b * y + p -> c * z; } The z-buffer just holds the smallest depth at the respective xy coordinate by somewhat casting rays to the polygon (I haven't quite got interpolation right yet so I'm using this slower method until I do) and determining the z coordinate from the reversed perspective projection formulas (which I got from here: double z = -(b*Ez*y + a*Ez*x - d*Ez)/(b*y + a*x + c*Ez - b*Ey - a*Ex); Where x and y are the pixel's coordinates on the screen; a, b, c, and d are the planes coefficients; Ex, Ey, and Ez are the eye's (camera's) coordinates. This last formula does not accurately give the exact vertices' z coordinate at their projected x and y coordinates on the screen, probably because of some floating point inaccuracy (i.e. I've seen it return something like 3.001 when the vertex's z-coordinate was actually 2.998). Here is the portion of code that hides the vertices that shouldn't be visible: for(i = 0; i < shape.nverts; ++i) { double dist = shape.verts[i].z; if(z_buffer[shape.verts[i].yp][shape.verts[i].xp].z < dist) shape.verts[i].visible = 0; else shape.verts[i].visible = 1; } How do I solve this issue? EDIT I've implemented the near and far planes of the frustum, with 24 bit accuracy, and now I have some questions: Is this what I have to do this in order to resolve the flickering? When I compare the z value of the vertex with the z value in the buffer, do I have to convert the z value of the vertex to z' using the formula, or do I convert the value in the buffer back to the original z, and how do I do that? What are some decent values for near and far? Thanks in advance.

  Read the article

• JPRT: A Build & Test System

  - by kto

  DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

  Read the article

• What Counts for a DBA: Humility

  - by drsql

  In football (the American sort, naturally,) there are a select group of players who really hope to never have their names called during the game. They are members of the offensive line, and their job is to protect other players so they can deliver the ball to the goal to score points. When you do hear their name called, it is usually because they made a mistake and the player that they were supposed to protect ended up flat on his back admiring the clouds in the sky instead of advancing towards the goal to scoring point. Even on the rare occasion their name is called for a good reason, it is usually because they were making up for a teammate who had made a mistake and they covered up for them. The role of offensive lineman is a very good analogy for the role of the admin DBA. As a DBA, you are called on to be barely visible and rarely heard, protecting the company data assets tenaciously, even though the enemies to our craft surround us on all sides:. Developers: Cries of ‘foul!’ often ensue when the DBA says that they want data integrity to be stringently enforced and that documentation is needed so they can support systems, mostly because every error occurrence in the enterprise will be initially blamed on the database and fall to the DBA to troubleshoot. Insisting too loudly may bring those cries of ‘foul’ that somewhat remind you of when your 2 year old daughter didn't want to go to bed. The result of this petulance is that the next "enemy" gets involved. Managers: The concerns that motivate DBAs to argue will not excite the kind of manager who gets his technical knowledge from a glossy magazine filled with buzzwords, charts, and pretty pictures. However, the other programmers in the organization will tickle the buzzword void with a stream of new-sounding ideas and technologies constantly, along with warnings that if we did care about data integrity and document things, the budget would explode! In contrast, the arguments for integrity of data and supportability tend to be about as exciting as watching grass grow, and far too many manager types seem to prefer to smoke it than watch it. Packaged Applications: The DBA is rarely given a chance to review a new application that is being demonstrated for the enterprise, and rarer still is the DBA that gets a veto of an application because the database it uses has clearly been created by an architect that won't read a data modeling book because he is already married. More often than not this leads to hours of work for the DBA trying to performance-tune a database with a menagerie of rules that must be followed to stay within the  application support agreement, such as no changing indexes on a third party schema even though there are 10 billion rows instead of the 10 thousand when the system was last optimized. Hardware Failures: Physical disks, networking devices, memory, and backup devices all come with a measure known as ‘mean time before failure’ and it is never listed in centuries or eons. More like years, and the term ‘mean’ indicates that half of the devices are expected to fail before that, which by my calendar means any hour of any day that it wants to fail it will. But the DBA sucks it up and does the task at hand with a humility that makes them nearly invisible to all but the most observant person in the organization. The best DBAs I know are so proactive in their relentless pursuit of perfection that they detect many of the bugs (which they seldom caused) in the system well before they become a problem. In the end the DBA gets noticed for one of same two reasons as the offensive lineman. You make a mistake, like dropping a critical production database that had never been backed up; or when a system crashes for any reason whatsoever and they are on the spot with troubleshooting and system restoration plans that have been well thought out, tested, and tested again. Not because there is any glory in it, but because it is what they do.   Note: The characteristics of the professions referred to in this blog are meant to be overstated stereotypes for humorous effect, and even some DBAs aren't quite this perfect. If you are reading this far and haven’t hand written a 10 page flaming comment about how you are a _______ and you aren’t like this, that is awesome. Not every situation applies to everyone, but if you have never worked with a bad packaged app, a magazine trained manager, programmers that aren’t team players, or hardware that occasionally failed, relax and go have a unicorn sandwich before you wake up.

  Read the article

• Inside BackgroundWorker

  - by João Angelo

  The BackgroundWorker is a reusable component that can be used in different contexts, but sometimes with unexpected results. If you are like me, you have mostly used background workers while doing Windows Forms development due to the flexibility they offer for running a background task. They support cancellation and give events that signal progress updates and task completion. When used in Windows Forms, these events (ProgressChanged and RunWorkerCompleted) get executed back on the UI thread where you can freely access your form controls. However, the logic of the progress changed and worker completed events being invoked in the thread that started the background worker is not something you get directly from the BackgroundWorker, but instead from the fact that you are running in the context of Windows Forms. Take the following example that illustrates the use of a worker in three different scenarios: – Console Application or Windows Service; – Windows Forms; – WPF. using System; using System.ComponentModel; using System.Threading; using System.Windows.Forms; using System.Windows.Threading; class Program { static AutoResetEvent Synch = new AutoResetEvent(false); static void Main() { var bw1 = new BackgroundWorker(); var bw2 = new BackgroundWorker(); var bw3 = new BackgroundWorker(); Console.WriteLine("DEFAULT"); var unspecializedThread = new Thread(() => { OutputCaller(1); SynchronizationContext.SetSynchronizationContext( new SynchronizationContext()); bw1.DoWork += (sender, e) => OutputWork(1); bw1.RunWorkerCompleted += (sender, e) => OutputCompleted(1); // Uses default SynchronizationContext bw1.RunWorkerAsync(); }); unspecializedThread.IsBackground = true; unspecializedThread.Start(); Synch.WaitOne(); Console.WriteLine(); Console.WriteLine("WINDOWS FORMS"); var windowsFormsThread = new Thread(() => { OutputCaller(2); SynchronizationContext.SetSynchronizationContext( new WindowsFormsSynchronizationContext()); bw2.DoWork += (sender, e) => OutputWork(2); bw2.RunWorkerCompleted += (sender, e) => OutputCompleted(2); // Uses WindowsFormsSynchronizationContext bw2.RunWorkerAsync(); Application.Run(); }); windowsFormsThread.IsBackground = true; windowsFormsThread.SetApartmentState(ApartmentState.STA); windowsFormsThread.Start(); Synch.WaitOne(); Console.WriteLine(); Console.WriteLine("WPF"); var wpfThread = new Thread(() => { OutputCaller(3); SynchronizationContext.SetSynchronizationContext( new DispatcherSynchronizationContext()); bw3.DoWork += (sender, e) => OutputWork(3); bw3.RunWorkerCompleted += (sender, e) => OutputCompleted(3); // Uses DispatcherSynchronizationContext bw3.RunWorkerAsync(); Dispatcher.Run(); }); wpfThread.IsBackground = true; wpfThread.SetApartmentState(ApartmentState.STA); wpfThread.Start(); Synch.WaitOne(); } static void OutputCaller(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "RunWorkerAsync".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); } static void OutputWork(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "DoWork".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); } static void OutputCompleted(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "RunWorkerCompleted".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); Synch.Set(); } } Output: //DEFAULT //bw1.RunWorkerAsync | Thread: 3 | IsThreadPool: False //bw1.DoWork | Thread: 4 | IsThreadPool: True //bw1.RunWorkerCompleted | Thread: 5 | IsThreadPool: True //WINDOWS FORMS //bw2.RunWorkerAsync | Thread: 6 | IsThreadPool: False //bw2.DoWork | Thread: 5 | IsThreadPool: True //bw2.RunWorkerCompleted | Thread: 6 | IsThreadPool: False //WPF //bw3.RunWorkerAsync | Thread: 7 | IsThreadPool: False //bw3.DoWork | Thread: 5 | IsThreadPool: True //bw3.RunWorkerCompleted | Thread: 7 | IsThreadPool: False As you can see the output between the first and remaining scenarios is somewhat different. While in Windows Forms and WPF the worker completed event runs on the thread that called RunWorkerAsync, in the first scenario the same event runs on any thread available in the thread pool. Another scenario where you can get the first behavior, even when on Windows Forms or WPF, is if you chain the creation of background workers, that is, you create a second worker in the DoWork event handler of an already running worker. Since the DoWork executes in a thread from the pool the second worker will use the default synchronization context and the completed event will not run in the UI thread.

  Read the article

• Developing Schema Compare for Oracle (Part 6): 9i Query Performance

  - by Simon Cooper

  All throughout the EAP and beta versions of Schema Compare for Oracle, our main request was support for Oracle 9i. After releasing version 1.0 with support for 10g and 11g, our next step was then to get version 1.1 of SCfO out with support for 9i. However, there were some significant problems that we had to overcome first. This post will concentrate on query execution time. When we first tested SCfO on a 9i server, after accounting for various changes to the data dictionary, we found that database registration was taking a long time. And I mean a looooooong time. The same database that on 10g or 11g would take a couple of minutes to register would be taking upwards of 30 mins on 9i. Obviously, this is not ideal, so a poke around the query execution plans was required. As an example, let's take the table population query - the one that reads ALL_TABLES and joins it with a few other dictionary views to get us back our list of tables. On 10g, this query takes 5.6 seconds. On 9i, it takes 89.47 seconds. The difference in execution plan is even more dramatic - here's the (edited) execution plan on 10g: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 108K| 939 || 1 | SORT ORDER BY | | 108K| 939 || 2 | NESTED LOOPS OUTER | | 108K| 938 ||* 3 | HASH JOIN RIGHT OUTER | | 103K| 762 || 4 | VIEW | ALL_EXTERNAL_LOCATIONS | 2058 | 3 ||* 20 | HASH JOIN RIGHT OUTER | | 73472 | 759 || 21 | VIEW | ALL_EXTERNAL_TABLES | 2097 | 3 ||* 34 | HASH JOIN RIGHT OUTER | | 39920 | 755 || 35 | VIEW | ALL_MVIEWS | 51 | 7 || 58 | NESTED LOOPS OUTER | | 39104 | 748 || 59 | VIEW | ALL_TABLES | 6704 | 668 || 89 | VIEW PUSHED PREDICATE | ALL_TAB_COMMENTS | 2025 | 5 || 106 | VIEW | ALL_PART_TABLES | 277 | 11 |------------------------------------------------------------------------------- And the same query on 9i: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 16P| 55G|| 1 | SORT ORDER BY | | 16P| 55G|| 2 | NESTED LOOPS OUTER | | 16P| 862M|| 3 | NESTED LOOPS OUTER | | 5251G| 992K|| 4 | NESTED LOOPS OUTER | | 4243M| 2578 || 5 | NESTED LOOPS OUTER | | 2669K| 1440 ||* 6 | HASH JOIN OUTER | | 398K| 302 || 7 | VIEW | ALL_TABLES | 342K| 276 || 29 | VIEW | ALL_MVIEWS | 51 | 20 ||* 50 | VIEW PUSHED PREDICATE | ALL_TAB_COMMENTS | 2043 | ||* 66 | VIEW PUSHED PREDICATE | ALL_EXTERNAL_TABLES | 1777K| ||* 80 | VIEW PUSHED PREDICATE | ALL_EXTERNAL_LOCATIONS | 1744K| ||* 96 | VIEW | ALL_PART_TABLES | 852K| |------------------------------------------------------------------------------- Have a look at the cost column. 10g's overall query cost is 939, and 9i is 55,000,000,000 (or more precisely, 55,496,472,769). It's also having to process far more data. What on earth could be causing this huge difference in query cost? After trawling through the '10g New Features' documentation, we found item 1.9.2.21. Before 10g, Oracle advised that you do not collect statistics on data dictionary objects. From 10g, it advised that you do collect statistics on the data dictionary; for our queries, Oracle therefore knows what sort of data is in the dictionary tables, and so can generate an efficient execution plan. On 9i, no statistics are present on the system tables, so Oracle has to use the Rule Based Optimizer, which turns most LEFT JOINs into nested loops. If we force 9i to use hash joins, like 10g, we get a much better plan: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 7587K| 3704 || 1 | SORT ORDER BY | | 7587K| 3704 ||* 2 | HASH JOIN OUTER | | 7587K| 822 ||* 3 | HASH JOIN OUTER | | 5262K| 616 ||* 4 | HASH JOIN OUTER | | 2980K| 465 ||* 5 | HASH JOIN OUTER | | 710K| 432 ||* 6 | HASH JOIN OUTER | | 398K| 302 || 7 | VIEW | ALL_TABLES | 342K| 276 || 29 | VIEW | ALL_MVIEWS | 51 | 20 || 50 | VIEW | ALL_PART_TABLES | 852K| 104 || 78 | VIEW | ALL_TAB_COMMENTS | 2043 | 14 || 93 | VIEW | ALL_EXTERNAL_LOCATIONS | 1744K| 31 || 106 | VIEW | ALL_EXTERNAL_TABLES | 1777K| 28 |------------------------------------------------------------------------------- That's much more like it. This drops the execution time down to 24 seconds. Not as good as 10g, but still an improvement. There are still several problems with this, however. 10g introduced a new join method - a right outer hash join (used in the first execution plan). The 9i query optimizer doesn't have this option available, so forcing a hash join means it has to hash the ALL_TABLES table, and furthermore re-hash it for every hash join in the execution plan; this could be thousands and thousands of rows. And although forcing hash joins somewhat alleviates this problem on our test systems, there's no guarantee that this will improve the execution time on customers' systems; it may even increase the time it takes (say, if all their tables are partitioned, or they've got a lot of materialized views). Ideally, we would want a solution that provides a speedup whatever the input. To try and get some ideas, we asked some oracle performance specialists to see if they had any ideas or tips. Their recommendation was to add a hidden hook into the product that allowed users to specify their own query hints, or even rewrite the queries entirely. However, we would prefer not to take that approach; as well as a lot of new infrastructure & a rewrite of the population code, it would have meant that any users of 9i would have to spend some time optimizing it to get it working on their system before they could use the product. Another approach was needed. All our population queries have a very specific pattern - a base table provides most of the information we need (ALL_TABLES for tables, or ALL_TAB_COLS for columns) and we do a left join to extra subsidiary tables that fill in gaps (for instance, ALL_PART_TABLES for partition information). All the left joins use the same set of columns to join on (typically the object owner & name), so we could re-use the hash information for each join, rather than re-hashing the same columns for every join. To allow us to do this, along with various other performance improvements that could be done for the specific query pattern we were using, we read all the tables individually and do a hash join on the client. Fortunately, this 'pure' algorithmic problem is the kind that can be very well optimized for expected real-world situations; as well as storing row data we're not using in the hash key on disk, we use very specific memory-efficient data structures to store all the information we need. This allows us to achieve a database population time that is as fast as on 10g, and even (in some situations) slightly faster, and a memory overhead of roughly 150 bytes per row of data in the result set (for schemas with 10,000 tables in that means an extra 1.4MB memory being used during population). Next: fun with the 9i dictionary views.

  Read the article

• "Guiding" a Domain Expert to Retire from Programming

  - by James Kolpack

  I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

  Read the article

• Storing non-content data in Orchard

  - by Bertrand Le Roy

  A CMS like Orchard is, by definition, designed to store content. What differentiates content from other kinds of data is rather subtle. The way I would describe it is by saying that if you would put each instance of a kind of data on its own web page, if it would make sense to add comments to it, or tags, or ratings, then it is content and you can store it in Orchard using all the convenient composition options that it offers. Otherwise, it probably isn't and you can store it using somewhat simpler means that I will now describe. In one of the modules I wrote, Vandelay.ThemePicker, there is some configuration data for the module. That data is not content by the definition I gave above. Let's look at how this data is stored and queried. The configuration data in question is a set of records, each of which has a number of properties: public class SettingsRecord { public virtual int Id { get; set;} public virtual string RuleType { get; set; } public virtual string Name { get; set; } public virtual string Criterion { get; set; } public virtual string Theme { get; set; } public virtual int Priority { get; set; } public virtual string Zone { get; set; } public virtual string Position { get; set; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Each property has to be virtual for nHibernate to handle it (it creates derived classed that are instrumented in all kinds of ways). We also have an Id property. The way these records will be stored in the database is described from a migration: public int Create() { SchemaBuilder.CreateTable("SettingsRecord", table => table .Column<int>("Id", column => column.PrimaryKey().Identity()) .Column<string>("RuleType", column => column.NotNull().WithDefault("")) .Column<string>("Name", column => column.NotNull().WithDefault("")) .Column<string>("Criterion", column => column.NotNull().WithDefault("")) .Column<string>("Theme", column => column.NotNull().WithDefault("")) .Column<int>("Priority", column => column.NotNull().WithDefault(10)) .Column<string>("Zone", column => column.NotNull().WithDefault("")) .Column<string>("Position", column => column.NotNull().WithDefault("")) ); return 1; } When we enable the feature, the migration will run, which will create the table in the database. Once we've done that, all we have to do in order to use the data is inject an IRepository<SettingsRecord>, which is what I'm doing from the set of helpers I put under the SettingsService class: private readonly IRepository<SettingsRecord> _repository; private readonly ISignals _signals; private readonly ICacheManager _cacheManager; public SettingsService( IRepository<SettingsRecord> repository, ISignals signals, ICacheManager cacheManager) { _repository = repository; _signals = signals; _cacheManager = cacheManager; } The repository has a Table property, which implements IQueryable<SettingsRecord> (enabling all kind of Linq queries) as well as methods such as Delete and Create. Here's for example how I'm getting all the records in the table: _repository.Table.ToList() And here's how I'm deleting a record: _repository.Delete(_repository.Get(r => r.Id == id)); And here's how I'm creating one: _repository.Create(new SettingsRecord { Name = name, RuleType = ruleType, Criterion = criterion, Theme = theme, Priority = priority, Zone = zone, Position = position }); In summary, you create a record class, a migration, and you're in business and can just manipulate the data through the repository that the framework is exposing. You even get ambient transactions from the work context.

  Read the article

• The Dreaded Startup Repair Loop on Win 7

  - by HighAltitudeCoder

  For most people, upgrading to Windows 7 has been a relatively painless process.  Not me.  I am in the unlucky 1% or less who had a somewhat less pleasant experience.  First, I cloned my entire onto a larger (and much faster) solid state hard drive, only experiencing minimal problems. Then, I bought the Retail version of Windows 7 Ultimate, took a deep breath and... oh yeah, I almost forgot - BACK UP THE COMPUTER.  The next morning I upgraded to Win 7 and everything seemed fine, until... I rebooted the system, the nice Windows 7 launch graphics come up, it's about to launch and AWWW, are you kidding me?!?!  Back to the BIOS splash screen?  Next comes the sequence of failure - attempt repair - unable to repair - do you want to wipe your hard drive decisions. Because I purchased the retail version, a number is provided where I could call Microsoft Tech support.  When I did, they instructed me to click "Install" from my installation CD, which did not work.  When I tried the "Upgrade" option, it reaches an impasse, telling you that yoiu have a newer version of Win 7, and thus cannot Upgrade.  If you choose "Install" you willl lose everything... files, programs, EVERYTHING.  Or at least this is what it tells you.  I was not willing to take the risk. To make things worse, I had installed a new antivirus software application before I realized my system was unstable (Trend Micro Titanium Internet Security), and this was causing additional problems. One interesting thing, and the only saving grace as it turns out, was that my system WOULD successfully reboot into the OS if I chose to restart it, rather than shut it down.  If I chose to shut down, I would have to go through the loop again until I was given the option to restart. As it turned out, I needed to update my BIOS.  I assumed that since I had updated my BIOS a long time ago to settings that were stable under Windows Vista Ultimate x64, I incorrectly expected Win 7 to adopt the same settings and didn't expect there to be any problems.  WRONG. My BIOS had a setting to halt the boot cycle if various kinds of errors were detected.  Windows Vista didn't care about this, but forget it under Windows 7.  I turned immediately corrected that BIOS setting.  Next, there were the two separate BIOS settings: enable USB mouse and enable USB keyboard.  The only sequence of events that would work were to start my reboot process over from stratch with a hard-wired non-usb keyboard and mouse.  Whent the system booted under these settings, it doesn't detect any errors due to either the mouse or keyboard, and actually booted for the first time in a long while (let me tell ya, that's an amazing experience after fiddling with settings for two entire weekends!) Next step: leave your old mouse and keyboard connected, but also connect your other two devices (mouse, keyboard) that use USB connections.  During the boot cycle, the operating system will not fail due to missing requirements during startup, and it will then pick up the new drivers necessary to use your new hardware. If you think you are in the clear here, you are wrong.  The next VERY IMPORTANT step is to remember to change your settings in the BIOS upon next startup.  Specifically, yoiu will need ot change your BIOS to enable USB mouse and enable USB keyboard input.  If you don't, Windows will detect an incompatibility upon the next startup, and you will be stuck once again in the endless cycle of reboot/Startup Repair/reboot/Startup Repair, without ever reaching a successful boot. Here's the thing - the BIOS and the drivers registered in Win 7 need to match.  If they don't, you're going to lose another weekend worrying and fiddling, all the while wondering if you've permanently damaged your hard drive beyond repair. (Sigh).  In the end, things worked out.  I must note that it is saddening to see how many posts there are out there that recommend just doing a clean install, as if it's the only option.  How many countless poor souls have lost their data, their backups, their pictures and videos, all for nothing other than the fact that the person giving advice just didn't know what to do at that point? My advice to you, try having a look at your BIOS settings first and making sure Win 7 can find your BIOS settings, and also disabling in your BIOS anything that might halt your system boot-up process if it encounters errors.

  Read the article

• returning correct multiTouch id

  - by Max

  I've spent countless hours on reading tutorials and looking at every question related to multiTouch from here and Stackoverflow. But I just cannot figure out how to do this correctly. I use a loop to get my pointerId, I dont see alot of people doing this but its the only way I've managed to get it somewhat working. I have two joysticks on my screen, one for moving and one for controlling my sprites rotation and the angle he shoots, like in Monster Shooter. Both these work fine. My problem is that when I Move my sprite at the same time as Im shooting, my touchingPoint for my movement is set to the touchingPoint of my shooting, since the x and y is higher on the touchingPoint of my shooting (moving-stick on left side of screen, shooting-stick on right side), my sprite speeds up, this creates an unwanted change in speed for my sprite. I will post my entire onTouch method here with some variable-changes to make it more understandable. Since I do not know where Im going wrong. public void update(MotionEvent event) { if (event == null && lastEvent == null) { return; } else if (event == null && lastEvent != null) { event = lastEvent; } else { lastEvent = event; } int pointerCount = event.getPointerCount(); for (int i = 0; i < pointerCount; i++) { int x = (int) event.getX(i); int y = (int) event.getY(i); int id = event.getPointerId(i); int action = event.getActionMasked(); int actionIndex = event.getActionIndex(); String actionString; switch (action) { case MotionEvent.ACTION_DOWN: actionString = "DOWN"; break; case MotionEvent.ACTION_UP: shooting=false; // when shooting is true, it shoots dragging=false; // when dragging is true, it moves actionString = "UP"; break; case MotionEvent.ACTION_POINTER_DOWN: actionString = "PNTR DOWN"; break; case MotionEvent.ACTION_POINTER_UP: shooting=false; dragging=false; actionString = "PNTR UP"; break; case MotionEvent.ACTION_CANCEL: shooting=false; dragging=false; actionString = "CANCEL"; break; case MotionEvent.ACTION_MOVE: try{ if((int) event.getX(id) > 0 && (int) event.getX(id) < touchingBox && (int) event.getY(id) > touchingBox && (int) event.getY(id) < view.getHeight()){ movingPoint.x = (int) event.getX(id); movingPoint.y = (int) event.getY(id); dragging = true; } else if((int) event.getX(id) > touchingBox && (int) event.getX(id) < view.getWidth() && (int) event.getY(id) > touchingBox && (int) event.getY(id) < view.getHeight()){ shootingPoint.x = (int) event.getX(id); shootingPoint.y = (int) event.getY(id); shooting=true; }else{ shooting=false; dragging=false; } }catch(Exception e){ } actionString = "MOVE"; break; default: actionString = ""; } Wouldnt post this much code if I wasnt at an absolute loss of what I'm doing wrong. I simply can not get a good understanding of how multiTouching works. basicly movingPoint changes for both my first and second finger. I bind it to a box, but aslong as I hold one finger within this box, it changes its value based on where my second finger touches. It moves in the right direction and nothing gives an error, the problem is the speed-change, its almost like it adds up the two touchingPoints.

  Read the article

• Stumbling Through: Visual Studio 2010 (Part II)

  I would now like to expand a little on what I stumbled through in part I of my Visual Studio 2010 post and touch on a few other features of VS 2010.  Specifically, I want to generate some code based off of an Entity Framework model and tie it up to an actual data source.  Im not going to take the easy way and tie to a SQL Server data source, though, I will tie it to an XML data file instead.  Why?  Well, why not?  This is purely for learning, there are probably much better ways to get strongly-typed classes around XML but it will force us to go down a path less travelled and maybe learn a few things along the way.  Once we get this XML data and the means to interact with it, I will revisit data binding to this data in a WPF form and see if I cant get reading, adding, deleting, and updating working smoothly with minimal code.  To begin, I will use what was learned in the first part of this blog topic and draw out a data model for the MFL (My Football League) - I dont want the NFL to come down and sue me for using their name in this totally football-related article.  The data model looks as follows, with Teams having Players, and Players having a position and statistics for each season they played: Note that when making the associations between these entities, I was given the option to create the foreign key but I only chose to select this option for the association between Player and Position.  The reason for this is that I am picturing the XML that will contain this data to look somewhat like this: <MFL> <Position/> <Position/> <Position/> <Team>     <Player>         <Statistic/>     </Player> </Team> </MFL> Statistic will be under its associated Player node, and Player will be under its associated Team node no need to have an Id to reference it if we know it will always fall under its parent.  Position, however, is more of a lookup value that will not have any hierarchical relationship to the player.  In fact, the Position data itself may be in a completely different xml file (something Id like to play around with), so in any case, a player will need to reference the position by its Id. So now that we have a simple data model laid out, I would like to generate two things based on it:  A class for each entity with properties corresponding to each entity property An IO class with methods to get data for each entity, either all instances, by Id or by parent. Now my experience with code generation in the past has consisted of writing up little apps that use the code dom directly to regenerate code on demand (or using tools like CodeSmith).  Surely, there has got to be a more fun way to do this given that we are using the Entity Framework which already has built-in code generation for SQL Server support.  Lets start with that built-in stuff to give us a base to work off of.  Right click anywhere in the canvas of our model and select Add Code Generation Item: So just adding that code item seemed to do quite a bit towards what I was intending: It apparently generated a class for each entity, but also a whole ton more.  I mean a TON more.  Way too much complicated code was generated now that code is likely to be a black box anyway so it shouldnt matter, but we need to understand how to make this work the way we want it to work, so lets get ready to do some stumbling through that text template (tt) file. When I open the .tt file that was generated, right off the bat I realize there is going to be trouble there is no color coding, no intellisense no nothing!  That is going to make stumbling through more like groping blindly in the dark while handcuffed and hopping on one foot, which was one of the alternate titles I was considering for this blog.  Thankfully, the community comes to my rescue and I wont have to cast my mind back to the glory days of coding in VI (look it up, kids).  Using the Extension Manager (Available under the Tools menu), I did a quick search for tt editor in the Online Gallery and quickly found the Tangible T4 Editor: Downloading and installing this was a breeze, and after doing so I got some color coding and intellisense while editing the tt files.  If you will be doing any customizing of tt files, I highly recommend installing this extension.  Next, well see if that is enough help for us to tweak that tt file to do the kind of code generation that we wantDid you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• View overlapping with RelativeLayout on Android 1.5

  - by Justin

  I am having a problem with views overlapping in a RelativeLayout on Android 1.5... Everything is working fine on Android 1.6 and above. I do understand that Android 1.5 has some issues with RelativeLayout, but I was not able to find anything on StackOverflow or the android beginners group for my specific problem. My layout consists of four sections, each of which are made up of a TextView, a Gallery, and another TextView aligned vertically: Running Apps Recent Apps Services Processes When all four sets of these items are displayed everything works fine. However, my app allows the user to specify that some of these are not displayed. If the user turns off Running Apps, Recent Apps, or Services then the remaining sections all of a sudden overlap eachother. Here is my code for the layout. I'm not sure what I am doing wrong. When the user turns off display of a section I use the View.GONE visibility setting: <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_vertical" android:layout_gravity="center_vertical" android:background="@null" > <!-- Running Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/running_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/running_title" /> <Gallery android:id="@+id/running_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/running_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_id" android:gravity="center_horizontal" /> <!-- Recent Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/recent_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_current_text_id" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/recent_title" /> <Gallery android:id="@+id/recent_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/recent_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_id" android:gravity="center_horizontal" /> <!-- Service Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/service_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_current_text_id" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/service_title" /> <Gallery android:id="@+id/service_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/service_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/service_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/service_gallery_id" android:gravity="center_horizontal" /> </RelativeLayout> I ommitted the xml for the Processes section in a (somewhat vain) attempt to keep this shorter... What can I do to make this work in Android 1.5? I don't think it is just a matter of reordering the views in the xml because it works fine when everything is displayed.

  Read the article

• How to convert a DataSet object into an ObjectContext (Entity Framework) object on the fly?

  - by Marcel

  Hi all, I have an existing SQL Server database, where I store data from large specific log files (often 100 MB and more), one per database. After some analysis, the database is deleted again. From the database, I have created both a Entity Framework Model and a DataSet Model via the Visual Studio designers. The DataSet is only for bulk importing data with SqlBulkCopy, after a quite complicated parsing process. All queries are then done using the Entity Framework Model, whose CreateQuery Method is exposed via an interface like this public IQueryable<TTarget> GetResults<TTarget>() where TTarget : EntityObject, new() { return this.Context.CreateQuery<TTarget>(typeof(TTarget).Name); } Now, sometimes my files are very small and in such a case I would like to omit the import into the database, but just have a an in-memory representation of the data, accessible as Entities. The idea is to create the DataSet, but instead of bulk importing, to directly transfer it into an ObjectContext which is accessible via the interface. Does this make sense? Now here's what I have done for this conversion so far: I traverse all tables in the DataSet, convert the single rows into entities of the corresponding type and add them to instantiated object of my typed Entity context class, like so MyEntities context = new MyEntities(); //create new in-memory context ///.... //get the item in the navigations table MyDataSet.NavigationResultRow dataRow = ds.NavigationResult.First(); //here, a foreach would be necessary in a true-world scenario NavigationResult entity = new NavigationResult { Direction = dataRow.Direction, ///... NavigationResultID = dataRow.NavigationResultID }; //convert to entities context.AddToNavigationResult(entity); //add to entities ///.... A very tedious work, as I would need to create a converter for each of my entity type and iterate over each table in the DataSet I have. Beware, if I ever change my database model.... Also, I have found out, that I can only instantiate MyEntities, if I provide a valid connection string to a SQL Server database. Since I do not want to actually write to my fully fledged database each time, this hinders my intentions. I intend to have only some in-memory proxy database. Can I do simpler? Is there some automated way of doing such a conversion, like generating an ObjectContext out of a DataSet object? P.S: I have seen a few questions about unit testing that seem somewhat related, but not quite exact.

  Read the article

• Problems with transitionWithView and animateWithDuration

  - by MusicMathTech

  I have problems with transitionWithView and animateWithDuration. One of my animateWithDuration blocks doesn't transition, it is a sudden change, and transitionWithView does not temporarily disable user interaction. I have checked the docs and believe I am doing everything correctly, but obviously something is wrong. Here are the two blocks of code: This is in my main View Controller ViewController which has three container views/child view controllers. This block moves one of the container views, but does not block the user from other interactions in ViewController while the transition is occurring. [UIView transitionWithView:self.view duration:0.5 options:UIViewAnimationOptionCurveEaseOut animations:^ { CGRect frame = _containerView.frame; frame.origin.y = self.view.frame.size.height - _containerView.frame.size.height; _containerView.frame = frame; }completion:^(BOOL finished) { // do something }]; This is in one of my container view controllers. The animation seems to have no effect as the text of the productTitleLabel and productDescriptionTextView changes suddenly as if the animation block does not exist. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [self.viewController toggleFlavoredOliveOilsTableView]; if (indexPath.row > 0) { NSDictionary *selectedCellDict = [[_flavoredOliveOilsDict objectForKey:@"Unflavored Olive Oils"] objectAtIndex:indexPath.row - 1]; [UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionTransitionCrossDissolve animations:^ { self.viewController.productTitleLabel.text = [_flavoredOliveOilsTableView cellForRowAtIndexPath:indexPath].textLabel.text; self.viewController.productDescriptionTextView.text = [selectedCellDict objectForKey:@"Description"]; }completion:nil]; if (indexPath.row == 1) { [self.viewController setProductDescriptionTextViewFrameForInformationTab]; } else { [self.viewController setProductDescriptionTextViewFrameForNonInformationTab]; //self.viewController.productImageView.image = [UIImage imageNamed:[selectedCellDict objectForKey:@"Image"]]; } } } I think the problems are somewhat related as most of my animation and transition blocks don't work completely as expected. Thanks for any help. Edit What I am trying to accomplish is moving a container view in ViewController and set the text and image properties of a label, text view, and image view; all of which are in the main view. The details of these properties are sent via the child view controller. The transitionWithView is in a method called toggleFlavoredOiveOilsTableView which is called in didSelectRowAtIndexPath. I think the problem is that I am trying to call two different animation/transition blocks at the same time.

  Read the article

• Populating a combobox on selectedindex change of another combobox

  - by Riju K K

  Hi, I have created a custom dialog UI, which contains two combobox with SQL server instance & on selection of one of SQLServer instance, another combobox has to be filled with name of Databases on that server instance. I am able to find filling combo with SQL server Instances I had written a similar CustomAction to fill the combobox with database names [CustomAction] public static ActionResult FillDatabases(Session xiSession) { xiSession.Log("Begin CustomAction"); xiSession.Log("Opening view"); View lView = xiSession.Database.OpenView("DELETE FROM ComboBox WHERE ComboBox.Property='DBNAME'"); lView.Execute(); lView = xiSession.Database.OpenView("SELECT * FROM ComboBox"); lView.Execute(); int Index = 1; //bool flag = false; try { Microsoft.SqlServer.Management.Smo.Server svr = new Microsoft.SqlServer.Management.Smo.Server(xiSession["DBSRVR"]); foreach (Microsoft.SqlServer.Management.Smo.Database db in svr.Databases ) { String dbName = db.Name; Record lRecord = xiSession.Database.CreateRecord(3); xiSession.Log("Setting record details"); lRecord.SetString(1, "DBNAME"); lRecord.SetInteger(2, Index); lRecord.SetString(3, db.Name); xiSession.Log("Adding record"); lView.Modify(ViewModifyMode.InsertTemporary, lRecord); ++Index; } } catch (Exception ex) { //logException(xiSession, ex); xiSession.Log(ex.Message ); } lView.Close(); xiSession.Log("Closing view"); lView.Close(); return ActionResult.Success; } I want to call these custom actions somewhat like shown below, <Binary Id="CustomActions.CA.dll" SourceFile="CustomActions.CA.dll" /> <CustomAction Id="FillServerInstances" BinaryKey="CustomActions.CA.dll" DllEntry="FillServerInstances" Execute="immediate" Return="check" /> <CustomAction Id="FillDatabases" BinaryKey="CustomActions.CA.dll" DllEntry="FillDatabases" Execute="immediate" Return="check" /> <InstallUISequence> <Custom Action="FillServerInstances" After="CostFinalize" /> <Custom Action="FillDatabases" After="FillServerInstances" /> </InstallUISequence> I need to show this Sqlserver selection custom dialog from another custom UI, in case user clicked on a pushbutton. Am I doing the right thing in the WiX code? Is there a better way in which combobox custom action fire only when user click on a pushbutton? "FillDatabases" custom action have to be fire whenever user select a new SQLServer instance. How do i do that? Thanks

  Read the article

• Eventlet or gevent or Stackless + Twisted, Pylons, Django and SQL Alchemy

  - by Khorkrak

  We're using Twisted extensively for apps requiring a great deal of asynchronous io. There are some cases where stuff is cpu bound instead and for that we spawn a pool of processes to do the work and have a system for managing these across multiple servers as well - all done in Twisted. Works great. The problem is that it's hard to bring new team members up to speed. Writing asynchronous code in Twisted requires a near vertical learning curve. It's as if humans just don't think that way naturally. We're considering a mixed approach perhaps. Maybe do the xmlrpc server part and process management in Twisted still but the other stuff in code that at least looks synchronous while not being as such. Then again I like explicit over implicit so hmmm. Anyway onto greenlets - how well does that stuff work? So there's Stackless and as you can see from my Gallentean avatar I'm well aware of the tremendous success in it's use for CCP's flagship EVE Online game first hand. What about Eventlet or gevent? Well for now only Eventlet works with Twisted. However gevent claims to be faster since it's not a pure python implementation it instead uses libevent. It also has fewer idiosyncrasies and defects supposedly. The documentation there is minimal in comparison to Eventlet and it's maintained by 1 guy as far as I can tell. This makes me leery but all great projects start this way so... Then there's PyPy - I haven't even finished reading about that one yet - just saw it in this thread: Drawbacks of Stackless. So confusing - I'm wondering what the heck to do - sounds like Eventlet is probably the best bet but is it really stable enough? Anyone out there have any experience with it? Should we go with Stackless instead as it's been around and is proven technology - just like Twisted is as well - and they do work together nicely. But still I hate having to have a separate version of Python to do this. what to do.... This somewhat obnoxious blog entry hit the nail on the head for me though: Asynchronous IO for Grownups We're stuck using MySQL as well - I never knew how great PostgreSQL was until having had to work on a production OLTP system in MySQL instead - but that's another story. But if that monkey patch thing really works then wow. Just wow.

  Read the article

• C++ vs Matlab vs Python as a main language for Computer Vision Postgraduate

  - by Hough

  Hi all, Firstly, sorry for a somewhat long question but I think that many people are in the same situation as me and hopefully they can also gain some benefit from this. I'll be starting my PhD very soon which involve the fields of computer vision, pattern recognition and machine learning. Currently, I'm using opencv (2.1) C++ interface and I especially like its powerful Mat class and the overloaded operations available for matrix and image seamless operations and transformations. I've also tried (and implemented many small vision projects) using opencv python interface (new bindings; opencv 2.1) and I really enjoy python's ability to integrate opencv, numpy, scipy and matplotlib. But recently, I went back to opencv C++ interface because I felt that the official python new bindings were not stable enough and no overloaded operations are available for matrices and images, not to mention the lack of machine learning modules and slow speeds in certain operations. I've also used Matlab extensively in the past and although I've used mex files and other means to speed up the program, I just felt that Matlab's performance was inadequate for real-time vision tasks, be it for fast prototyping or not. When the project becomes larger and larger, many tasks have to be re-written in C and compiled into Mex files increasingly and Matlab becomes nothing more than a glue language. Here comes the sub-questions: For postgrad studies in these fields (machine learning, vision, pattern recognition), what is your main or ideal programming language for rapid prototyping of ideas and testing algorithms contained in papers? For postgrad studies, can you list down the pros and cons of using the following languages? C++ (with opencv + gsl + svmlib + other libraries) vs Matlab (with all its toolboxes) vs python (with the imcomplete opencv bindings + numpy + scipy + matplotlib). Are there computer vision PhD/postgrad students here who are using only C++ (with all its availabe libraries including opencv) without even needing to resort to Matlab or python? In other words, given the current existing computer vision or machine learning libraries, is C++ alone sufficient for fast prototyping of ideas? If you're currently using Java or C# for your postgrad work, can you list down the reasons why they should be used and how they compare to other languages in terms of available libraries? What is the de facto vision/machine learning programming language and its associated libraries used in your university research group? Thanks in advance.

  Read the article

• Jquery-UI tabs : Double loading of the default tab

  - by Stephane

  I use jqueryui-tabs to display a tabbed UI. here is how my markup looks in a MasterPage: <div id="channel-tabs" class="ui-tabs"> <ul class="ui-tabs-nav"> <li><%=Html.ActionLink("Blogs", "Index", "Blog", new { query = Model.Query, lang = Model.SelectedLanguage, fromTo = Model.FromTo, filters = Model.FilterId }, new{ title="Blog Results" }) %></li> <li><%=Html.ActionLink("Forums", "Index", "Forums", new { query = Model.Query, lang = Model.SelectedLanguage, fromTo = Model.FromTo, filters = Model.FilterId }, null) %></li> <li><%=Html.ActionLink("Twitter", "Index", "Twitter", new { query = Model.Query, lang = Model.SelectedLanguage, fromTo = Model.FromTo, filters = Model.FilterId }, null) %></li> </ul> <div id="Blog_Results"> <asp:ContentPlaceHolder ID="ResultPlaceHolder" runat="server"> </asp:ContentPlaceHolder> </div> If the content is loaded via ajax, I return a partial view with the content of the tab. If the content is loaded directly, I load a page that include the content in the ContentPlaceHolder. somewhat like this : <asp:Content ID="Content2" ContentPlaceHolderID="BlogPlaceHolder" runat="server"> <%=Html.Partial("Partial",Model) %> </asp:Content> //same goes for the other tabs. With this in place, if I access the url "/Forums" It loads the forum content in the Blog tab first, trigger the ajax load of the Blog tab and replace the content with the blog content. I tried putting a different placeholder for each tab, but that didn't fix everything either, since when loading "/Forums" it will sure load the forum tab, but the Blog tab will show up first. Furthermore, when using separate placeholders, If I load the "/Blogs" url, It will first load the content statically in the Blog contentplaceholder and then trigger an ajax call to load it a second time and replace it. If I just link the tab to the hashtag, then when loading the forum tabs, I won't get the blog content... How would you achieve the expected behaviour? I feel like I might have a deeper probelm in the organization of my views. Is putting the tabs in the masterpage the way to go? Maybe I should just hijax the links manually and not rely on jquery-ui tabs to do the work for me. I cannot load all tabs by default and display them using the hash tags, I need an ajax loading because it is a search process that can be long. So to sum up : /Forum should load the forum tab, and let the other tabs be loaded with an ajax call when clicking on it. /Twitter should load the twitter tab and let the other tabs.... the same goes for /Blogs and any tabs I would add later. Any idea to have this working properly?

  Read the article

• Sentiment analysis with NLTK python for sentences using sample data or webservice?

  - by Ke

  I am embarking upon a NLP project for sentiment analysis. I have successfully installed NLTK for python (seems like a great piece of software for this). However,I am having trouble understanding how it can be used to accomplish my task. Here is my task: I start with one long piece of data (lets say several hundred tweets on the subject of the UK election from their webservice) I would like to break this up into sentences (or info no longer than 100 or so chars) (I guess i can just do this in python??) Then to search through all the sentences for specific instances within that sentence e.g. "David Cameron" Then I would like to check for positive/negative sentiment in each sentence and count them accordingly NB: I am not really worried too much about accuracy because my data sets are large and also not worried too much about sarcasm. Here are the troubles I am having: All the data sets I can find e.g. the corpus movie review data that comes with NLTK arent in webservice format. It looks like this has had some processing done already. As far as I can see the processing (by stanford) was done with WEKA. Is it not possible for NLTK to do all this on its own? Here all the data sets have already been organised into positive/negative already e.g. polarity dataset http://www.cs.cornell.edu/People/pabo/movie-review-data/ How is this done? (to organise the sentences by sentiment, is it definitely WEKA? or something else?) I am not sure I understand why WEKA and NLTK would be used together. Seems like they do much the same thing. If im processing the data with WEKA first to find sentiment why would I need NLTK? Is it possible to explain why this might be necessary? I have found a few scripts that get somewhat near this task, but all are using the same pre-processed data. Is it not possible to process this data myself to find sentiment in sentences rather than using the data samples given in the link? Any help is much appreciated and will save me much hair! Cheers Ke

  Read the article

• c# Properties.Settings.Default Doesn't work as expected

  - by Jack

  I've been working on a program to automate my backup checks with LogMeIn backup (a windows forms based program). I now need a way to store user settings, to save information easily. I've never worked with the Application/User settings that is somewhat "built-in" - and decided to try it, but ran into problems. I added four settings for now: IncludeCriteria (Specialized.StringCollection) ExcludeCriteria (Specialized.StringCollection) ReportPath (string) ReportType (int) But the behavior doesn't act as expected (go figure). After saving some values in my program, I go back into edit/view my settings values using the VS 2008 settings editor. None of my values are stored. While I think this may be because those values are just default values, wouldn't that be where they can be stored/read/changed? Here is my load form code (still very unrefined): private void setupForm() { txtPath.Text = BackupReport.Properties.Settings.Default.ReportPath == null ? "" : BackupReport.Properties.Settings.Default.ReportPath; if (BackupReport.Properties.Settings.Default.ReportType == 0) { radioHTML.Checked = true; } else radioExcel.Checked = true; if (BackupReport.Properties.Settings.Default.IncludeCriteria.Count > 0) { listIncludeCriteria.DataSource = Properties.Settings.Default.IncludeCriteria; //foreach (string s in Properties.Settings.Default.IncludeCriteria) // listIncludeCriteria.Items.Add(s); } if (BackupReport.Properties.Settings.Default.ExcludeCriteria.Count > 0) { listExcludeCriteria.DataSource = BackupReport.Properties.Settings.Default.ExcludeCriteria; //foreach (string s in Properties.Settings.Default.ExcludeCriteria) // listExcludeCriteria.Items.Add(s); } } listIncludeCriteria is just a listbox. When the user saves I call this method: private void saveSettings() { //var settings = BackupReport.Properties.Settings; if (txtPath.Text != "") { BackupReport.Properties.Settings.Default.ReportPath = txtPath.Text; } if (listIncludeCriteria.Items.Count > 0) { //BackupReport.Properties.Settings.Default.IncludeCriteria = (StringCollection)listIncludeCriteria.Items.AsQueryable(); foreach (var i in listIncludeCriteria.Items) { if (!isIncludeDuplicate(i.ToString())) BackupReport.Properties.Settings.Default.IncludeCriteria.Add(i.ToString()); } } if (listExcludeCriteria.Items.Count > 0) { //BackupReport.Properties.Settings.Default.ExcludeCriteria = (StringCollection)listExcludeCriteria.Items.AsQueryable(); foreach (var i in listExcludeCriteria.Items) { if (!isExcludeDuplicate(i.ToString())) Properties.Settings.Default.ExcludeCriteria.Add(i.ToString()); } } if (radioExcel.Checked == true) BackupReport.Properties.Settings.Default.ReportType = 1; else BackupReport.Properties.Settings.Default.ReportType = 0; BackupReport.Properties.Settings.Default.Save(); //Properties.Settings.Default.Save(); this.DialogResult = DialogResult.OK; this.Close(); } The wierd thing is when the form loads, the path I put in the first time seems to come up (ReportPath) - even the listBoxes are populated with a bunch of crap I put in - yet I cant find these values anywhere. Any help would be appreciated! Josh

  Read the article

• Doubt about adopting CI (Hudson) into an existing automated Build Process (phing, svn)

  - by maraspin

  OUR CURRENT BUILD PROCESS We're a small team of developers (2 to 4 people depending on project) who currently use Phing to deploy code to a staging environment, before going live. We keep our code in a SVN repo, where the trunk holds current active development and, at certain times, we do make branches that we test and then (if successful), tag and export to the staging env. If everything goes well there too, we finally deploy'em in production servers. Actions are highly automated, but always triggered by human intervention. THE DOUBT We'd now like to introduce Continuous Integration (with Hudson) in the process; unfortunately we have a few doubts about activity syncing, since we're afraid that CI could somewhat interfere with our build process and cause certain problems. Considering that an automated CI cycle has a certain frequency of automatically executed actions, we in fact only see 2 possible cases for "integration", each with its own problems: Case A: each CI cycle produces a new branch with its own name; we do use such a name to manually (through phing as it happens now) export the code from the SVN to the staging env. The problem I see here is that (unless specific countermeasures are taken) the number of branches we have can grow out of control (let's suppose we commit often, so that we have a fresh new build/branch every N minutes). Case B: each CI cycle creates a new branch named 'current', for instance, which is tagged with a unique name only when we manually decide to export it to staging; the current branch, at any case is then deleted, as soon as the next CI cycle starts up. The problem we see here is that a new cycle could kick in while someone is tagging/exporting the 'current' branch to staging thus creating an inconsistent build (but maybe here I'm just too pessimist, since I confess I don't know whether SVN offers some built-in protection against this). With all this being said, I was wondering if anyone with similar experiences could be so kind to give us some hints on the subject, since none of the approaches depicted above looks completely satisfing to us. Is there something important we just completely left off in the overall picture? Thanks for your attention &, in advance, for your help!

  Read the article

• Does .NET have a built in IEnumerable for multiple collections?

  - by Bryce Wagner

  I need an easy way to iterate over multiple collections without actually merging them, and I couldn't find anything built into .NET that looks like it does that. It feels like this should be a somewhat common situation. I don't want to reinvent the wheel. Is there anything built in that does something like this: public class MultiCollectionEnumerable<T> : IEnumerable<T> { private MultiCollectionEnumerator<T> enumerator; public MultiCollectionEnumerable(params IEnumerable<T>[] collections) { enumerator = new MultiCollectionEnumerator<T>(collections); } public IEnumerator<T> GetEnumerator() { enumerator.Reset(); return enumerator; } IEnumerator IEnumerable.GetEnumerator() { enumerator.Reset(); return enumerator; } private class MultiCollectionEnumerator<T> : IEnumerator<T> { private IEnumerable<T>[] collections; private int currentIndex; private IEnumerator<T> currentEnumerator; public MultiCollectionEnumerator(IEnumerable<T>[] collections) { this.collections = collections; this.currentIndex = -1; } public T Current { get { if (currentEnumerator != null) return currentEnumerator.Current; else return default(T); } } public void Dispose() { if (currentEnumerator != null) currentEnumerator.Dispose(); } object IEnumerator.Current { get { return Current; } } public bool MoveNext() { if (currentIndex >= collections.Length) return false; if (currentIndex < 0) { currentIndex = 0; if (collections.Length > 0) currentEnumerator = collections[0].GetEnumerator(); else return false; } while (!currentEnumerator.MoveNext()) { currentEnumerator.Dispose(); currentEnumerator = null; currentIndex++; if (currentIndex >= collections.Length) return false; currentEnumerator = collections[currentIndex].GetEnumerator(); } return true; } public void Reset() { if (currentEnumerator != null) { currentEnumerator.Dispose(); currentEnumerator = null; } this.currentIndex = -1; } } }

  Read the article

• .NET RegEx "Memory Leak" investigation

  - by Kevin Pullin

  I recently looked into some .NET "memory leaks" (i.e. unexpected, lingering GC rooted objects) in a WinForms app. After loading and then closing a huge report, the memory usage did not drop as expected even after a couple of gen2 collections. Assuming that the reporting control was being kept alive by a stray event handler I cracked open WinDbg to see what was happening... Using WinDbg, the !dumpheap -stat command reported a large amount of memory was consumed by string instances. Further refining this down with the !dumpheap -type System.String command I found the culprit, a 90MB string used for the report, at address 03be7930. The last step was to invoke !gcroot 03be7930 to see which object(s) were keeping it alive. My expectations were incorrect - it was not an unhooked event handler hanging onto the reporting control (and report string), but instead it was held on by a System.Text.RegularExpressions.RegexInterpreter instance, which itself is a descendant of a System.Text.RegularExpressions.CachedCodeEntry. Now, the caching of Regexs is (somewhat) common knowledge as this helps to reduce the overhead of having to recompile the Regex each time it is used. But what then does this have to do with keeping my string alive? Based on analysis using Reflector, it turns out that the input string is stored in the RegexInterpreter whenever a Regex method is called. The RegexInterpreter holds onto this string reference until a new string is fed into it by a subsequent Regex method invocation. I'd expect similar behaviour by hanging onto Regex.Match instances and perhaps others. The chain is something like this: Regex.Split, Regex.Match, Regex.Replace, etc Regex.Run RegexScanner.Scan (RegexScanner is the base class, RegexInterpreter is the subclass described above). The offending Regex is only used for reporting, rarely used, and therefore unlikely to be used again to clear out the existing report string. And even if the Regex was used at a later point, it would probably be processing another large report. This is a relatively significant problem and just plain feels dirty. All that said, I found a few options on how to resolve, or at least work around, this scenario. I'll let the community respond first and if no takers come forward I will fill in any gaps in a day or two.

  Read the article

• Galleria jQuery plugin briefly shows all images in IE 7 & 8

  - by hollyb

  I'm using the galleria jQuery plugin on a site. When the gallery first loads, all of the images appear briefly & vertically in ie 7 & 8. This doesn't happen when i isolate the gallery, only when i put it on a somewhat heavy page. This leads me to believe that it happens when the page is a little slow to load. Does anybody know a way to fix this? I feel like an overflow: hidden should fix this, but I've applied it along with a height in every container I could think of. Anybody have any ideas? Here is my css: .galleria{list-style:none;width:350px; overflow:hidden; height: 70px;} .galleria li{display:block;width:50px;height:50px;overflow:hidden;float:left;margin:4px 10px 20px 0;} .galleria li a{display:none;} .galleria li div{position:absolute;display:none;top:0;left:180px;} .galleria li div img{cursor:pointer;} .galleria li.active div img,.galleria li.active div{display:block;} .galleria li img.thumb{cursor:pointer;top:auto;left:auto;display:block;width:auto;height:auto} .galleria li .caption{display: inline;padding-top:.5em; width: 300px; } * html .galleria li div span{width:350px;} /* MSIE bug */ html: <ul class="gallery"> <li class="active"><img src="1.jpg" cap="A great veiw by so and so. This is a long block of info.<br /><span style=color:#666;>Photo by: Billy D. Williams</span>" alt="Image01"></li> <li><img src="2.jpg" cap="A mountain <span style=color:#666;>Photo by: Billy D. Williams</span>" alt="Image01"></li> <li><img src="3.jpg" cap="Another witty caption <span style=color:#666;>Photo by: Billy D. Williams</span>" alt="Image01"></li> <li><img src="4.jpg" cap="<span style=color:#666;>Photo by: Billy D. Williams</span>" alt="Image01"></li> </ul>

  Read the article

• Moving from Linear Probing to Quadratic Probing (hash collisons)

  - by Nazgulled

  Hi, My current implementation of an Hash Table is using Linear Probing and now I want to move to Quadratic Probing (and later to chaining and maybe double hashing too). I've read a few articles, tutorials, wikipedia, etc... But I still don't know exactly what I should do. Linear Probing, basically, has a step of 1 and that's easy to do. When searching, inserting or removing an element from the Hash Table, I need to calculate an hash and for that I do this: index = hash_function(key) % table_size; Then, while searching, inserting or removing I loop through the table until I find a free bucket, like this: do { if(/* CHECK IF IT'S THE ELEMENT WE WANT */) { // FOUND ELEMENT return; } else { index = (index + 1) % table_size; } while(/* LOOP UNTIL IT'S NECESSARY */); As for Quadratic Probing, I think what I need to do is change how the "index" step size is calculated but that's what I don't understand how I should do it. I've seen various pieces of code, and all of them are somewhat different. Also, I've seen some implementations of Quadratic Probing where the hash function is changed to accommodated that (but not all of them). Is that change really needed or can I avoid modifying the hash function and still use Quadratic Probing? EDIT: After reading everything pointed out by Eli Bendersky below I think I got the general idea. Here's part of the code at http://eternallyconfuzzled.com/tuts/datastructures/jsw_tut_hashtable.aspx: 15 for ( step = 1; table->table[h] != EMPTY; step++ ) { 16 if ( compare ( key, table->table[h] ) == 0 ) 17 return 1; 18 19 /* Move forward by quadratically, wrap if necessary */ 20 h = ( h + ( step * step - step ) / 2 ) % table->size; 21 } There's 2 things I don't get... They say that quadratic probing is usually done using c(i)=i^2. However, in the code above, it's doing something more like c(i)=(i^2-i)/2 I was ready to implement this on my code but I would simply do: index = (index + (index^index)) % table_size; ...and not: index = (index + (index^index - index)/2) % table_size; If anything, I would do: index = (index + (index^index)/2) % table_size; ...cause I've seen other code examples diving by two. Although I don't understand why... 1) Why is it subtracting the step? 2) Why is it diving it by 2?

  Read the article

< Previous Page | 71 72 73 74 75 76 77 78 79 80 81 82  | Next Page >