Search Results

Search found 22040 results on 882 pages for 'process improvement'.

Page 308/882 | < Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >

  • Business Layer Pattern on Rails? MVCL

    - by Fabiano PS
    That is a broad question, and I appreciate no short/dumb asnwers like: "Oh that is the model job, this quest is retarded (period)" PROBLEM Where I work at people created a system over 2 years for managing the manufacture process over demand in the most simplified still broad as possible, involving selling, buying, assemble, The system is coded over Ruby On Rails. The result has been changed lots of times and the result is a mess on callbacks (some are called several times), 200+ models, and fat controllers: Total bad. The QUESTION is, if there is a gem, or pattern designed to handle Rails large app logic? The logic whould be able to fully talk to models (whose only concern would be data format handling and validation) What I EXPECT is to reduce complexity from various controllers, and hard to track callbacks into files with the responsibility to handle a business operation logic. In some cases there is the need to wait for a response, in others, only validation of the input is enough and a bg process would take place. ie: -- Sell some products (need to wait the operation to finish) 1. Set a View able to get the products input 2. Controller gets the product list inputed by employee and call the logic Logic::ExecuteWithResponse('sell', 'products', :prods => @product_list_with_qtt, :when => @date, :employee => current_user() ) This Logic would handle buying order, assemble order, machine schedule, warehouse reservation, and others

    Read the article

  • segmentation fault on Unix - possible stack corruption

    - by bob
    hello, i'm looking at a core from a process running in Unix. Usually I can work my around and root into the backtrace to try identify a memory issue. In this case, I'm not sure how to proceed. Firstly the backtrace only gives 3 frames where I would expect alot more. For those frames, all the function parameters presented appears to completely invalid. There are not what I would expect. Some pointer parameters have the following associated with them - Cannot access memory at address Would this suggest some kind of complete stack corruption. I ran the process with libumem and all the buffers were reported as being clean. umem_status reported nothing either. so basically I'm stumped. What is the likely causes? What should I look for in code since libumem appears to have reported no errors. Any suggestions on how I can debug furhter? any extra features in mdb I should consider? thank you.

    Read the article

  • How can I turn a column name into a result value in SQL Server?

    - by Brennan
    I have a table which has essentially boolean values in a legacy database. The column names are stored as string values in another table so I need to match the column names of one table to a string value in another table. I know there has to be a way to do this directly with SQL in SQL Server but it is beyond me. My initial thought was to use PIVOT but it is not enabled by default and enabling it would likely be a difficult process with pushing that change to the Production database. I would prefer to use what is enabled by default. I am considering using COALESCE to translate the boolean value to the string that value that I need. This will be a manual process. I think I will also use a table variable to insert the results of the first query into that variable and use those results to do the second query. I still have the problem that the columns are on a single row so I wish I could easily pivot the values to put the column names in the result set as strings. But if I could easily do that I could easily write the query with a sub-select. Any tips are welcome.

    Read the article

  • Set up WLAN in 3-level house

    - by Balint Erdi
    I'm having a hard time setting up the network in our house. It has three levels (basement, ground floor, first level). The WLAN is set up by an ASUS RT-N12 router which provides perfect coverage for the ground floor and the basement. However, I set up my "home office" in the basement where the signal barely arrived. So I purchased a TP-Link TL-WA901ND (300 Mbps) Access Point which I set up in the other corner of the ground floor to expand the ASUS router's range. I used the AP's Repeater mode for that. The distance between my computer and the TP-Link AP is 6-7 meters. There is a staircase going down from the ground floor to the basement so there are no solid walls between the computer and the AP. This setup mostly works (I am writing this from the basement) but it is not reliable (the signal strength sometimes goes down to ~40% of the max) sometimes so I wonder if I am doing it correctly or if there is a better way. Screenshot of the router's and the AP's dashboard screen follow: Any comments on what I am doing wrong or hints for improvement are appreciated. Thank you. UPDATE Tried one more thing, setting up the TP-LINK AP in Access Point mode. That way, I can make it use a different SSID. I enabled WDS/Bridge so that it expands the range of the ASUS router (see screenshot). That does not work, either, if I connect to the network set up by the TP-LINK device (PELSTER-2), I can't reach the external network (the Internet). It seems the problem always comes back to this, the TP-LINK does not have access to the external network, whatever its mode of operation.

    Read the article

  • Forking in PHP on Windows

    - by Doug Kavendek
    We are running PHP on a Windows server (a source of many problems indeed, but migrating is not an option currently). There are a few points where a user-initiated action will need to kick off a few things that take a while and about which the user doesn't need to know if they succeed or fail, such as sending off an email or making sure some third-party accounts are updated. If I could just fork with pcntl_fork(), this would be very simple, but the PCNTL functions are not available in Windows. It seems the closest I can get is to do something of this nature: exec( 'php-cgi.exe somescript.php' ); However, this would be far more complicated. The actions I need to kick off rely on a lot of context that already will exist in the running process; to use the above example, I'd need to figure out the essential data and supply it to the new script in some way. If I could fork, it'd just be a matter of letting the parent process return early, leaving the child to work on a few more things. I've found a few people talking about their own work in getting various PCNTL functions compiled on Windows, but none seemed to have anything available (broken links, etc). Despite this question having practically the same name as mine, it seems the problem was more execution timeout than needing to fork. So, is my best option to just refactor a bit to deal with calling php-cgi, or are there other options? Edit: It seems exec() won't work for this, at least not without me figuring some other aspect of it, as it waits until the call returns. I figured I could use START, sort of like exec( 'start php-cgi.exe somescript.php' );, but it still waits until the other script finishes.

    Read the article

  • Memory mapped files and "soft" page faults. Unavoidable?

    - by Robert Oschler
    I have two applications (processes) running under Windows XP that share data via a memory mapped file. Despite all my efforts to eliminate per iteration memory allocations, I still get about 10 soft page faults per data transfer. I've tried every flag there is in CreateFileMapping() and CreateFileView() and it still happens. I'm beginning to wonder if it's just the way memory mapped files work. If anyone there knows the O/S implementation details behind memory mapped files I would appreciate comments on the following theory: If two processes share a memory mapped file and one process writes to it while another reads it, then the O/S marks the pages written to as invalid. When the other process goes to read the memory areas that now belong to invalidated pages, this causes a soft page fault (by design) and the O/S knows to reload the invalidated page. Also, the number of soft page faults is therefore directly proportional to the size of the data write. My experiments seem to bear out the above theory. When I share data I write one contiguous block of data. In other words, the entire shared memory area is overwritten each time. If I make the block bigger the number of soft page faults goes up correspondingly. So, if my theory is true, there is nothing I can do to eliminate the soft page faults short of not using memory mapped files because that is how they work (using soft page faults to maintain page consistency). What is ironic is that I chose to use a memory mapped file instead of a TCP socket connection because I thought it would be more efficient. Note, if the soft page faults are harmless please note that. I've heard that at some point if the number is excessive, the system's performance can be marred. If soft page faults intrinsically are not significantly harmful then if anyone has any guidelines as to what number per second is "excessive" I'd like to hear that. Thanks.

    Read the article

  • wcf 4.0 service on IIS7

    - by Jan
    I am currently developing a service with wcf 4.0 (visual studio 2010 RC). When I try my service on the Visual Studio Development Server, it all works perfect. However, when I tree to run my service on IIS7 on a windows 7 machine, the service doesn't work anymore. (I already changed the framework version on my application pool). When I call an operation on the service, like the default operation GetData when I create a service, I get an error. I used the WCF test client to connect to the service. When I call the operation on the service, the Visual Studio Just-In-Time debugger shows the following message: An unhandled win32 exception occured in w3wp.exe The Just-In-Time debugger was launched without necessary security permissions. To debug this proces, the JIT debugger must be run as an administrator. Would you like to debug the proces? As far as I know, I am running Visual Studio as an administrator and this is probably the process that starts the JIT debugger. The only option I have is to debug the W3WP process, which is probably not the right thing to do. What can I do the make the Service to run on IIS7?

    Read the article

  • Wizard form in Struts

    - by Kuntal Basu
    I am creating a wizard in Struts. It cotains 4 steps. For Each step I have separate ActionClass say:- Step1Action.java Step2Action.java Step3Action.java Step4Action.java and in each class there are 2 methods input() and process(). input() method is for showing the page in input mode process() method is will be use for processing the submitted data (if validation is ok) I am carrying all data upto the last step in a session. And saving all of them in database in the last step Similaly 4 action tags in struts.xml like :- <action name="step1" class="com.mycomp.myapp.action.Step1Action1" method="input"> <result name="success" type="redirectAction">step2</result> <result name="input">/view/step1.jsp</result> </action> <action name="step2" class="com.mycomp.myapp.action.Step1Action2" method="input"> <result name="success" type="redirectAction">step3</result> <result name="input">/view/step2.jsp</result> </action> But I think I am going wrong. Please Tell me How will I handle This case?

    Read the article

  • SQL (mySQL) update some value in all records processed by a select

    - by jdmuys
    I am using mySQL from their C API, but that shouldn't be relevant. My code must process records from a table that match some criteria, and then update the said records to flag them as processed. The lines in the table are modified/inserted/deleted by another process I don't control. I am afraid in the following, the UPDATE might flag some records erroneously since the set of records matching might have changed between step 1 and step 3. SELECT * FROM myTable WHERE <CONDITION>; # step 1 <iterate over the selected set of lines. This may take some time.> # step 2 UPDATE myTable SET processed=1 WHERE <CONDITION> # step 3 What's the smart way to ensure that the UPDATE updates all the lines processed, and only them? A transaction doesn't seem to fit the bill as it doesn't provide isolation of that sort: a recently modified record not in the originally selected set might still be targeted by the UPDATE statement. For the same reason, SELECT ... FOR UPDATE doesn't seem to help, though it sounds promising :-) The only way I can see is to use a temporary table to memorize the set of rows to be processed, doing something like: CREATE TEMPORARY TABLE workOrder (jobId INT(11)); INSERT INTO workOrder SELECT myID as jobId FROM myTable WHERE <CONDITION>; SELECT * FROM myTable WHERE myID IN (SELECT * FROM workOrder); <iterate over the selected set of lines. This may take some time.> UPDATE myTable SET processed=1 WHERE myID IN (SELECT * FROM workOrder); DROP TABLE workOrder; But this seems wasteful and not very efficient. Is there anything smarter? Many thanks from a SQL newbie.

    Read the article

  • Database INSERT does not take place

    - by reggie
    My code is as follows: <?php include("config.php"); $ip=$_SERVER['REMOTE_ADDR']; if($_POST['id']) { $id=$_POST['id']; $id = mysql_escape_String($id); $ip_sql=mysql_query("select ip_add from Voting_IP where mes_id_fk='$id' and ip_add='$ip'"); $count=mysql_num_rows($ip_sql); if($count==0) { $sql = "update Messages set up=up+1 where mes_id='$id'"; mysql_query($sql); $sql_in = "insert into Voting_IP (mes_id_fk,ip_add) values ('$id','$ip')"; mysql_query($sql_in) or die(mysql_error()); echo "<script>alert('Thanks for the vote');</script>"; } else { echo "<script>alert('You have already voted');</script>"; } $result=mysql_query("select up from Messages where mes_id='$id'"); $row=mysql_fetch_array($result); $up_value=$row['up']; echo "<img src='button.png' width='110' height='90'>"; echo $up_value; } ?> My problem is that the insert process does not take place at all. The script tags echos an alert box. Even the img tag is echoed to the web page. But the insert process does not take place. The config file is fine. Note: This code works on my local machine which has PHP 5.3 but it does not work on the server which has PHP 5.2. Any advice?

    Read the article

  • PLKs and Web Service Software Factory

    - by Nix
    We found a bug in Web Service Software Factory a description can be found here. There has been no updates on it so we decided to download the code and fix it ourself. Very simple bug and we patched it with maybe 3 lines of code. However* we have now tried to repackage it and use it and are finding that this is seemingly an impossible process. Can someone please explain to me the process of PLKs? I have read all about them but still don't understand what is really required to distribute a VS package. I was able to get it to load and run using a PLK obtained from here, but i am assuming that you have to be a partner to get a functional PLK that will be recognized on other peoples systems? Every time i try and install this on a different computer I get a "Package Load Failure". Is the reason I am getting errors because I am not using a partner key? Is there any other way around this? For instance is there any way we can have an "internal" VS package that we can distribute? Edit Files I had to change to get it to work. First run devenv PostInstall.proj Generate your plks and replace ##Package PLK## (.resx files) --Just note that package version is not the class name but is "Web Service Software Factory: Modeling Edition" -- And you need to remove the new lines from the key ProductDefinitionRegistryFragment.wxi line 1252(update version to whatever version you used in plk) Uncomment all // [VSShell::ProvideLoadKey("Standard", Constant in .tt files.

    Read the article

  • Creating nodes porgramatically in Drupal 6

    - by John
    Hey, I have been searching for how to create nodes in Drupal 6. I found some entries here on stackoverflow, but the questions seemed to either be for older versions or the solutions did not work for me. Ok, so here is my current process for trying to create $node = new stdClass(); $node->title = "test title"; $node->body = "test body"; $node->type= "story"; $node->created = time(); $node->changed = $node->created; $node->status = 1; $node->promote = 1; $node->sticky = 0; $node->format = 1; $node->uid = 1; node_save( $node ); When I execute this code, the node is created, but when I got the administration page, it throws the following errors: warning: Invalid argument supplied for foreach() in C:\wamp\www\steelylib\includes\menu.inc on line 258. warning: Invalid argument supplied for foreach() in C:\wamp\www\steelylib\includes\menu.inc on line 258. user warning: Duplicate entry '36' for key 1 query: INSERT INTO node_comment_statistics (nid, last_comment_timestamp, last_comment_name, last_comment_uid, comment_count) VALUES (36, 1269980590, NULL, 1, 0) in C:\wamp\www\steelylib\sites\all\modules\nodecomment\nodecomment.module on line 409. warning: Invalid argument supplied for foreach() in C:\wamp\www\steelylib\includes\menu.inc on line 258. warning: Invalid argument supplied for foreach() in C:\wamp\www\steelylib\includes\menu.inc on line 258. I've looked at different tutorials, and all seem to follow the same process. I'm not sure what I am doing wrong. I am using Drupal 6.15. When I roll back the database (to right before I made the changes) the errors are gone. Any help is appreciated!

    Read the article

  • Is it possible to use OAuth starting from the service provider website?

    - by Brian Armstrong
    I want to let people create apps that use my API and authenticate them with OAuth. Normally this process starts from the consumer service website (say TwitPic) and they request an access token from the service provider (Twitter). The user is then taken to the service provider website where they have to allow/deny access to to the consumer. I'm wondering if it's possible to initiate this process from the service provider website instead. So in this example you would start on Twitter's site, and maybe there is a section marked "do you want to turn on access for TwitPic?". If you click yes, it passes the access token directly to TwitPic which now has access to your account. Basically, fewer steps. I'm looking at the OAuth docs and it looks like the request token is generated on the consumer side and used later to turn it into an access token. So it's not really designed with what I described above in mind, but I thought there might be a way. http://oauth.net/core/1.0/ (Search for "steps") Thanks!

    Read the article

  • WF performance with new 20,000 persisted workflow instances each month

    - by Nikola Stjelja
    Windows Workflow Foundation has a problem that is slow when doing WF instances persistace. I'm planning to do a project whose bussiness layer will be based on WF exposed WCF services. The project will have 20,000 new workflow instances created each month, each instance could take up to 2 months to finish. What I was lead to belive that given WF slownes when doing peristance my given problem would be unattainable given performance reasons. I have the following questions: Is this true? Will my performance be crap with that load(given WF persitance speed limitations) How can I solve the problem? We currently have two possible solutions: 1. Each new buisiness process request(e.g. Give me a new drivers license) will be a new WF instance, and the number of persistance operations will be limited by forwarding all status request operations to saved state values in a separate database. 2. Have only a small amount of Workflow Instances up at any give time, without any persistance ofso ever(only in case of system crashes etc.), by breaking each workflow stap in to a separate worklof and that workflow handling each business process request instance in the system that is at that current step(e.g. I'm submitting my driver license reques form, which is step one... we have 100 cases of that, and my step one workflow will handle every case simultaneusly). I'm very insterested in solution for that problem. If you want to discuss that problem pleas be free to mail me at [email protected]

    Read the article

  • Application doesn't exit with 0 threads

    - by Bryce Wagner
    We have a WinForms desktop application, which is heavily multithreaded. 3 threads run with Application.Run and a bunch of other background worker threads. Getting all the threads to shut down properly was kind of tricky, but I thought I finally got it right. But when we actually deployed the application, users started experiencing the application not exiting. There's a System.Threading.Mutex to prevent them from running the app multiple times, so they have to go into task manager and kill the old one before they can run it again. Every thread gets a Thread.Join before the main thread exits, and I added logging to each thread I spawn. According to the log, every single thread that starts also exits, and the main thread also exits. Even stranger, running SysInternals ProcessExplorer show all the threads disappear when the application exits. As in, there are 0 threads (managed or unmanaged), but the process is still running. I can't reproduce this on any developers computers or our test environment, and so far I've only seen it happen on Windows XP (not Vista or Windows 7 or any Windows Server). How can a process keep running with 0 threads?

    Read the article

  • Fork or copy a users browser session in IE

    - by jmoeller
    Is it possible to fork a users session (or do something similar) in a Internet Explorer plugin? I want to process the page the user is on when they click a button in the toolbar. To avoid interrupting the users browsing, I'd like to "copy" everything so I can parse and process the page in the background. The processing can involve things such as loading the content of the result links on a Google search, if that's where the button was clicked. So - what I basically want is to imitate "Ctrl+N" but hide the window from the user, so they won't be interrupted. As you can see, if you fill out and submit the form on http://www.snee.com/xml/crud/posttest.html and press "Ctrl+N", everything posted will still appear in the new window, but it won't post the data twice. I was thinking of somehow copying the IWebBrowser2, but: I'm not sure if that's possible (I haven't been able to find any information on MSDN) I don't know if it copies the sessions as well. Creating a new instance of the IWebBrowser2 and simply navigating to the current URL isn't a valid solution as POST-variables of course doesn't get carried over.

    Read the article

  • Current wisdom on SQL Server and Hyperthreading?

    - by BradC
    Lots of articles out there (see Slava Oks's original SQL 2000 article and Kevin Kline's SQL 2005 update) recommend disabling hyperthreading on SQL servers, or at least testing your specific workload before enabling it on your servers. This issue is gradually becoming less relevant as true multi-core processors replace hyperthreaded ones, but what's the current wisdom on this issue? Does this advice change any with SQL 2005 64-bit, or SQL 2008, or Windows Server 2008? Ideally, this should be tested in advance in a staging environment, but what about for servers that have already made it into production with HT enabled? How can I tell if performance issues we're experiencing might be related to HT? Is there some specific combination of perfmon counters that might point me in that direction, as opposed to all the other things I normally pursue when working on improving SQL performance? Edit: This is especially attractive because of the potential for an across the board improvement for some of my high-cpu servers, but the client is going to want to see something concrete that helps me identify which servers really could benefit from disabling hyperthreading. Of course, conventional performance troubleshooting is ongoing, but sometimes any little bit helps.

    Read the article

  • Locking issues with replacing files on a website

    - by Moe Sisko
    I want to replace existing files on an IIS website with updated versions. Say these files are large pdf documents, which can be accessed via hyperlinks. The site is up 24x7, so I'm concerned about locking issues when a file is being updated at exactly the same time that someone is trying to read the file. The files are updated using C# code run on the server. I can think of two options for opening the file for writing. Option 1) Open the file for writing, using FileShare.Read : using (FileStream stream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.Read)) While this file is open, and a user requests the same file for reading in a web browser via a hyperlink, the document opens up as a blank page. Option 2) Open the file for writing using FileShare.None : using (FileStream stream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None)) While this file is open, and a user requests the same file for reading in a web browser via a hyperlink, the browser shows an error. In IE 8, you get HTTP 500, "The website cannot display the page", and in Firefox 3.5, you get : "The process cannot access the file because it is being used by another process." The browser behaviour kind of makes sense, and seem reasonable. I guess its highly unlikely that a user will attempt to read a file at exactly the same time you are updating it. It would be nice if somehow, the file update was atomic, like updating a database with SQL wrapped around a transaction. I'm wondering if you guys worry about this sort of thing, and prefer either of the above options, or even have other options of your own for updating files.

    Read the article

  • Which technology is best suited to store and query a huge readonly graph?

    - by asmaier
    I have a huge directed graph: It consists of 1.6 million nodes and 30 million edges. I want the users to be able to find all the shortest connections (including incoming and outgoing edges) between two nodes of the graph (via a web interface). At the moment I have stored the graph in a PostgreSQL database. But that solution is not very efficient and elegant, I basically need to store all the edges of the graph twice (see my question PostgreSQL: How to optimize my database for storing and querying a huge graph). It was suggested to me to use a GraphDB like neo4j or AllegroGraph. However the free version of AllegroGraph is limited to 50 million nodes and also has a very high-level API (RDF), which seems too powerful and complex for my problem. Neo4j on the other hand has only a very low level API (and the python interface is not mature yet). Both of them seem to be more suited for problems, where nodes and edges are frequently added or removed to a graph. For a simple search on a graph, these GraphDBs seem to be too complex. One idea I had would be to "misuse" a search engine like Lucene for the job, since I'm basically only searching connections in a graph. Another idea would be, to have a server process, storing the whole graph (500MB to 1GB) in memory. The clients could then query the server process and could transverse the graph very quickly, since the graph is stored in memory. Is there an easy possibility to write such a server (preferably in Python) using some existing framework? Which technology would you use to store and query such a huge readonly graph?

    Read the article

  • Silverlight 4 seems like starving of memory

    - by Marco
    I have been playing a bit with Silverlight and try to port my Silverlight 3.0 application to Silverlight 4.0. My application loads different XAP files and upon a user request create an instance of a Xaml user control and adds it to the main container, in a sort of MEF approach in order I can have an extensible and pluggable application. The application is pretty huge and to keep acceptable the performances and the initial loading I have built up some helper classes to load in the background all pages and user controls that might be used later on. On Silverlight 3.0 everything was running smoothly without any problem so far. Switching to SL 4.0 I have noticed that when the process approaches to create the instances of the user controls the layout freezes unexpectedly for a minute and sometimes for more. Looking at the task manager the memory usage of IE jumps from 50MB to 400MB and sometimes up to 1.5 GB. If the process won't take that much the layout is rendered properly even though the memory usage is still extremely high. Otherwise everything crashes due to out of memory exception. Running the same application compiled in SL3, the memory used is about 200MB when all the usercontrols are loaded. Time spent to load the application in SL3 is about 10 seconds, while it takes up to 3 mins in SL4 There are no transparencies, no opacities set, no effects and animations in the layout. User controls are instantied on the fly and added or removed in the visual tree on purpose when the user switches from one screen to another. The resources are all cleaned properly when a usercontrol is removed from the visual tree to allow the GC to operate in the background. I may do something wrong but I could not figure out where exactly nail out the source of this problem. As far as I know there is no memory profiler in SL4 that can help me out to find where to look at. But again I could not be updated on new debugging tools available.

    Read the article

  • ADO 2.8, VMWare and SQL Server - sudden bulk dropped connections

    - by CodeByMoonlight
    We have an overworked server currently running a single SQL Server 2000 instance on physical hardware, and about 40 different apps interact with it on a daily basis. Last year, the RAID controller failed and we had no spare, so IT Support hurriedly migrated it overnight to a copy running on a VMWare Server. While it was on that server everything ran much quicker due to it being a big improvement in spec. However, the biggest app using it had occasional serious errors which never occurred on physical hardware. Specifically, several times a week it would disconnect batches of users - anywhere from just ten to hundreds at once, and all at the same time. It didn't affect any particular users or PCs or offices - all were affected equally. The only common thing was the app, which is a VB6 app using ADO 2.8 to connect. The other apps connecting to that virtualised instance of SQL Server seemingly had no problems, although they were (and are) responsible for only a tiny fraction of the work involving this server. The upshot is that after about two weeks of loving the speed and hating the random mass disconnections (which we were never able to find a cause for), we sadly took the decision to return to physical hardware and the disconnections vanished. Now we've reached the point where the old server just can't handle all that's being asked of it, and we're intending to migrate everything to 2 or more other servers. The snag is that there's a good chance they'll have to be virtual ones again. Given what happened last time, I'm trying to find out what possible reasons there could be for these mass disconnections. We were running VMWare ESX, but the network is Novell-based. Also, the server had a linked server setup to connect to an Informix server using a known-to-be-buggy ODBC driver, and this is used throughout the day. Any ideas on the cause(s)?

    Read the article

  • How to use SQLAlchemy to dump an SQL file from query expressions to bulk-insert into a DBMS?

    - by Mahmoud Abdelkader
    Please bear with me as I explain the problem, how I tried to solve it, and my question on how to improve it is at the end. I have a 100,000 line csv file from an offline batch job and I needed to insert it into the database as its proper models. Ordinarily, if this is a fairly straight-forward load, this can be trivially loaded by just munging the CSV file to fit a schema, but I had to do some external processing that requires querying and it's just much more convenient to use SQLAlchemy to generate the data I want. The data I want here is 3 models that represent 3 pre-exiting tables in the database and each subsequent model depends on the previous model. For example: Model C --> Foreign Key --> Model B --> Foreign Key --> Model A So, the models must be inserted in the order A, B, and C. I came up with a producer/consumer approach: - instantiate a multiprocessing.Process which contains a threadpool of 50 persister threads that have a threadlocal connection to a database - read a line from the file using the csv DictReader - enqueue the dictionary to the process, where each thread creates the appropriate models by querying the right values and each thread persists the models in the appropriate order This was faster than a non-threaded read/persist but it is way slower than bulk-loading a file into the database. The job finished persisting after about 45 minutes. For fun, I decided to write it in SQL statements, it took 5 minutes. Writing the SQL statements took me a couple of hours, though. So my question is, could I have used a faster method to insert rows using SQLAlchemy? As I understand it, SQLAlchemy is not designed for bulk insert operations, so this is less than ideal. This follows to my question, is there a way to generate the SQL statements using SQLAlchemy, throw them in a file, and then just use a bulk-load into the database? I know about str(model_object) but it does not show the interpolated values. I would appreciate any guidance for how to do this faster. Thanks!

    Read the article

  • Key Navigation Not Working With SL3 Treeview

    - by Chris
    I have a treeview in SL3 that is bound to a hierarchical list. Something has changed with regards to being able to navigate through the list using the up and down arrow keys. At one point, during the development of this application, I could start at the root process in the tree view, press the Enter key, and the root process would expand, showing all children processes. Some of the child processes are parent nodes for other processes. So, that functionality would work fine. Then, if I would navigate to a child node that is a parent, and press Enter, that node would expand. From that point, if I would navigate to a child node of the parent node, and then press the Up arrow key, it should select whatever item is directly above it, in this case, the corresponding parent node, but won't. It's like you can't navigate, using the UP Arrow key, to a child's parent, if you have selected the child. You can navigate down, just not UP, if the next item above it is a folder/parent node. I have no clue as to how this happened, as this functionality used to work fine, and now it doesn't. Any help would be appreciated. Thanks! Chris

    Read the article

  • If I wanted to make a Pac-Man Game?

    - by SoulBeaver
    I am immediately placing this as a community wiki thing. I don't want to ask for help in programming yet or have even a specific question about programming, but rather the process and the resources needed to make such a game. To put it simply: My college friend and I decided to give ourselves a really big challenge to further our skills in programming. In six months time we want to show ourselves a Pac-Man game. Pac-Man will be AI-controlled like the Ghosts and whichever Pac-Man lives the longest after a set of tries wins. This isn't like anything we've done so far. The goal here, for me, isn't to create a perfect game, but to try and complete it, learn a whole bunch in the process. Even if I don't finish in the time, which is a good possibility, I would want to have at least tried this. So my question is this: How should I start preparing myself? I already have started vector math, matrices, all that fun stuff. My desired platform would be DirectX 9.0c; is that advisable? Keep in mind that this is not a preference just for this project, but I wish to have some kind of future in graphics develepment, so I want to pick a platform that is future-safe. As for the game development in general, what should I take into consideration? I have never done a real game before, so any and all advise to development of mid-scale projects( if this would be a mid-scale project ) is greatly appreciated. My main concerns are the pit-falls and demotivators. Sorry if the question is so vague. If it doesn't belong here, then I will remove it. Otherwise, any and all advise regarding making larger projects is greatly appreciated.

    Read the article

  • WPF User Control is causing Out of Memory Exception

    - by Chairman Meow
    Looking for a free spell checking solution, I thought I was so smart in doing this but I guess not. I have created a windows form based application and I want the form to add a user specified amount of user controls (with textboxes) on to a panel. The user can then click some button and the controls on this panel are cleared and new ones are added. The user does something and the process is repeated. Now, I wanted these textboxes to support spell checking and looked all over for a free solution. WPF textboxes support spell checking where the ones in regular win forms do not. I thought I would be able to use these WPF textboxes by adding them to an ElementHost object which is, in turn, within a panel. This panel would be a user control. So, in my application, I would be able to add instances of these user controls onto the form and make use of .NET's spell checking goodness. This actually worked but after using the application for a while, found that the application would eventually freeze on me due to out of memory errors. I have pinpointed the memory errors to these WPF controls since this problem does not happen with normal textboxes. When the window is opened and the number of controls is specified, this is pretty much how the controls are added: Dim xOffset As Integer = 0 For i As Integer = 0 To theNumber Dim myUserControl As New SpecialUserControl() myPanel.Controls.Add(myUserControl) myUserControl.Location = New Point(7, 7) myUserControl.Location = New Point(xOffset, 7) xOffset = xOffset + 207 Next Note that: myPanel is a panel on a form SpecialUserControl is the user control with WPF textbox (within an ElementHost object) When the user pressed a button, the panel is cleared: myUserControl.Controls.Clear() The user can then repeat the process. There are a lot of results on the internet when I tried to find a solution and I'm thinking that the problem I am having is due to the fact that the WPF control is not going away even after clearing the panel. Following this conclusion, I have tried different solutions regarding disposing these controls or setting them to nothing but the memory problem keeps occurring. If someone could give me some advice or ideas here, I'd really appreciate it.

    Read the article

< Previous Page | 304 305 306 307 308 309 310 311 312 313 314 315  | Next Page >