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  • [.NET Performance Counter] "System.ComponentModel.Win32Exception: Access is denied" is thrown when c

    - by Ricky
    Hi guys: Calling PerformanceCounterCategory.Create() below on my machine thorws out this exception: System.ComponentModel.Win32Exception: Access is denied Do you know what's the issue about it? Thank you! if (!PerformanceCounterCategory.Exists("MyCategory")) { CounterCreationDataCollection counters = new CounterCreationDataCollection(); CounterCreationData avgDurationBase = new CounterCreationData(); avgDurationBase.CounterName = "average time per operation base"; avgDurationBase.CounterHelp = "Average duration per operation execution base"; avgDurationBase.CounterType = PerformanceCounterType.AverageBase; counters.Add(avgDurationBase); // create new category with the counters above PerformanceCounterCategory.Create("MyCategory", "Sample category for Codeproject", PerformanceCounterCategoryType.SingleInstance, counters); }

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  • Why is drawing to OnPaint graphics faster than image graphics?

    - by Tesserex
    I'm looking for a way to speed up the drawing of my game engine, which is currently the significant bottleneck, and is causing slowdowns. I'm on the verge of converting it over to XNA, but I just noticed something. Say I have a small image that I've loaded. Image img = Image.FromFile("mypict.png"); We have a picturebox on the screen we want to draw on. So we have a handler. pictureBox1.Paint += new PaintEventHandler(pictureBox1_Paint); I want our loaded image to be tiled on the picturebox (this is for a game, after all). Why on earth is this code: void pictureBox1_Paint(object sender, PaintEventArgs e) { for (int y = 0; y < 16; y++) for (int x = 0; x < 16; x++) e.Graphics.DrawImage(image, x * 16, y * 16, 16, 16); } over 25 TIMES FASTER than this code: Image buff = new Bitmap(256, 256, PixelFormat.Format32bppPArgb); // actually a form member void pictureBox1_Paint(object sender, PaintEventArgs e) { using (Graphics g = Graphics.FromImage(buff)) { for (int y = 0; y < 16; y++) for (int x = 0; x < 16; x++) g.DrawImage(image, x * 16, y * 16, 16, 16); } e.Graphics.DrawImage(buff, 0, 0, 256, 256); } To eliminate the obvious, I've tried commenting out the last e.Graphics.DrawImage (which means I don't see anything, but it gets rid a call that isn't in the first example). I've also left in the using block (needlessly) in the first example, but it's still just as blazingly fast. I've set properties of g to match e.Graphics - things like InterpolationMode, CompositingQuality, etc, but nothing I do bridges this incredible gap in performance. I can't find any difference between the two Graphics objects. What gives? My test with a System.Diagnostics.Stopwatch says that the first code snippet runs at about 7100 fps, while the second runs at a measly 280 fps. My reference image is VS2010ImageLibrary\Objects\png_format\WinVista\SecurityLock.png, which is 48x48 px, and which I modified to be 72 dpi instead of 96, but those made no difference either.

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  • StackOverflow in VB.NET SQLite query

    - by Majgel
    I have an StackOverflowException in one of my DB functions that I don't know how to deal with. I have a SQLite database with one table "tblEmployees" that holds records for each employees (several thousand posts) and usually this function runs without any problem. But sometimes after the the function is called a thousand times it breaks with an StackOverflowException at the line "ReturnTable.Load(reader)" with the message: An unhandled exception of type 'System.StackOverflowException' occurred in System.Data.SQLite.dll If I restart the application it has no problem to continue with the exact same post it last crashed on. I can also make the exactly same DB-call from SQLite Admin at the crash time without no problems. Here is the code: Public Function GetNextEmployeeInQueue() As String Dim NextEmployeeInQueue As String = Nothing Dim query As [String] = "SELECT FirstName FROM tblEmployees WHERE Checked=0 LIMIT 1;" Try Dim ReturnTable As New DataTable() Dim mycommand As New SQLiteCommand(cnn) mycommand.CommandText = query Dim reader As SQLiteDataReader = mycommand.ExecuteReader() ReturnTable.Load(reader) reader.Close() If ReturnTable.Rows.Count > 0 Then NextEmployeeInQueue = ReturnTable.Rows(0)("FirstName").ToString() Else MsgBox("No more employees found in queue") End If Catch fail As Exception MessageBox.Show("Error: " & fail.Message.ToString()) End Try If NextEmployeeInQueue IsNot Nothing Then Return NextEmployeeInQueue Else Return "No more records in queue" End If End Function When crashes, the reader has "Property evaluation failed." in all values. I assume there is some problem with allocated memory that isn't released correctly, but can't figure out what object it's all about. The DB-connection opens when the DB-class object is created and closes on main form Dispose. Should I maybe dispose the mycommand object every time in a finally block? But wouldn't that result in a closed DB-connection?

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  • Recommendation for high performance WPF Chart

    - by Ajaxx
    We're working on a WPF-based desktop application that charts financial markets information (candlestick charts, overlayed indicator curves, volume, etc). The charts are displayed in real-time with responses to market ticks being shown in real-time (updating one to two times per second is probably a reasonable display refresh policy). We've been looking for a software package (commercial is fine by us) that has the capability of displaying these charts. Additionally, we'd like to have an approach that can render the initial amount of data in a reasonable timeframe (give or take 100-200ms from the time we hand the data over to a complete render on screen). Also we view multiple charts (5-10) simultaneously so a solution that chews up 50% of my CPU to display one chart really isn't going to work well. Has anyone had any good experiences with charting controls. We've had to hand roll the last few charts we've done and I'd prefer not to do it again. Solutions that can make use of the GPU to minimize CPU utilization would be nice as well.

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  • Drupal 6 vs Drupal 7 performance

    - by lifecoder
    Hi all. I want to start new project and stuck without idea what version to use. I have huge expirience with D6, and also one project (module developement) for D7. It looks like D7 slower, have bigger memory consumption and also have a lack of documentation by the moment. I don't need new CCK, Views and other - looks like I'll coding all features needed as modules. Is D7 have sweet parts now, or better way is develop project under D6? What way you choose for yourself, and why?

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  • Mysql Algorithm for Determining Closest Colour Match

    - by buggedcom
    I'm attempting to create a true mosaic application. At the moment I have one mosaic image, ie the one the mosaic is based on and about 4000 images from my iPhoto library that act as the image library. I have already done my research and analysed the mosaic image. I've converted it into 64x64 slices each of 8 pixels. I've calculated the average colour for each slice and assertain the r, g, b and brightness (Luminance (perceived option 1) = (0.299*R + 0.587*G + 0.114*B)) value. I have done the same for each of the image library photos. The mosaic slices table looks like so. slice_id, slice_image_id, slice_slice_id, slice_image_column, slice_image_row, slice_colour_hex, slice_rgb_red, slice_rgb_blue, slice_rgb_green, slice_rgb_brightness The image library table looks like so. upload_id, upload_file, upload_colour_hex, upload_rgb_red, upload_rgb_green, upload_rgb_blue, upload_rgb_brightness So basically I'm reading the image slices from the slices table into PHP and then pulling out the appropriate images from the library table based on the colour hexs. My trouble is that I've been on this too long and probably had too many energy drinks so am not concentrating properly, I can't figure out the way to pick out the nearest colour neighbor if the appropriate hex code doesn't exist. Any ideas on the perfect query? NB: I know pulling out the slices one by one is not ideal however the mosaic is only rebuilt periodically so a sudden burst in the mysql load doesn't really bother me, however if there us a way to pull the images out all at once that would also be a massive bonus.

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  • Searching Week-wise/Month-wise record counts(number) and the StartDate+EndDate(datetime) of the Week

    - by Muzaffar Ali Rana
    I have a question in connection to this question earlier posted by me:- http://stackoverflow.com/questions/2452984/daily-weekly-monthly-record-count-search-via-storedprocedure I want to have the Count of Calls on Weekly-basis and Monthly-basis, Daily-basis issue is resolved. ISSUE NUMBER @1:Weekly-basis Count of Calls and Start-Date and End-Date of Week I have searched the Start-Date and End-Date of Week including their individual Count of Calls as well in the below-mentioned query. But the problem is that I could not get the result in one single table, although I have used the Temporary Tables(#TempTable+#TempTable2). Kindly help me in this regards. NOTE:Table Creation commented as for executing more than once. ----- *** TABLE CREATION OF #TempTable & #TempTable2 *** ---------- --CREATE TABLE #TempTable( StartDate datetime,EndDate datetime,CallCount numeric(18,5)) --CREATE TABLE #TempTable2( StartDate datetime,EndDate datetime,CallCount numeric(18,5)) DECLARE @StartDate datetime,@EndDate datetime,@StartDateTemp1 datetime,@StartDateTemp2 datetime,@EndDateTemp datetime,@Period varchar(50); SET @StartDate='1/1/2010'; SET @EndDate='2/28/2010'; SET @StartDateTemp1=@StartDate; SET @StartDateTemp2=DATEADD(dd, 7, @StartDate ); SET @Period='Weekly'; IF (@Period = 'Weekly') BEGIN WHILE ((@StartDate <= @StartDateTemp1) AND (@StartDateTemp2 <= @EndDate)) BEGIN IF((@StartDateTemp1 < @StartDateTemp2 ) AND (@StartDateTemp1 != @StartDateTemp2) ) BEGIN SELECT convert(varchar, @StartDateTemp1, 106) AS 'Start Date', convert(varchar, @StartDateTemp2, 106) AS 'End Date', COUNT(*) AS 'Call Count' FROM TRN_Call WHERE (CallTime = @StartDateTemp1 AND CallTime <= @StartDateTemp2 ); END SET @StartDateTemp1 = DATEADD(dd, 7, @StartDateTemp1); SET @StartDateTemp2 = DATEADD(dd, 7, @StartDateTemp2); END END ISSUE NUMBER @2:Monthly-basis Count of Calls and Start-Date and End-Date of Week In this case, I have the same search, but will have to search the Call Counts plus the Start-Date and End-Date of the Month. Kindly help me in this regards as well.

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  • SQL Quey slow in .NET application but instantaneous in SQL Server Management Studio

    - by user203882
    Here is the SQL SELECT tal.TrustAccountValue FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = 70402 AND ta.TrustAccountID = 117249 AND tal.trustaccountlogid = ( SELECT MAX (tal.trustaccountlogid) FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = 70402 AND ta.TrustAccountID = 117249 AND tal.TrustAccountLogDate < '3/1/2010 12:00:00 AM' ) Basicaly there is a Users table a TrustAccount table and a TrustAccountLog table. Users: Contains users and their details TrustAccount: A User can have multiple TrustAccounts. TrustAccountLog: Contains an audit of all TrustAccount "movements". A TrustAccount is associated with multiple TrustAccountLog entries. Now this query executes in milliseconds inside SQL Server Management Studio, but for some strange reason it takes forever in my C# app and even timesout (120s) sometimes. Here is the code in a nutshell. It gets called multiple times in a loop and the statement gets prepared. cmd.CommandTimeout = Configuration.DBTimeout; cmd.CommandText = "SELECT tal.TrustAccountValue FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = @UserID1 AND ta.TrustAccountID = @TrustAccountID1 AND tal.trustaccountlogid = (SELECT MAX (tal.trustaccountlogid) FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = @UserID2 AND ta.TrustAccountID = @TrustAccountID2 AND tal.TrustAccountLogDate < @TrustAccountLogDate2 ))"; cmd.Parameters.Add("@TrustAccountID1", SqlDbType.Int).Value = trustAccountId; cmd.Parameters.Add("@UserID1", SqlDbType.Int).Value = userId; cmd.Parameters.Add("@TrustAccountID2", SqlDbType.Int).Value = trustAccountId; cmd.Parameters.Add("@UserID2", SqlDbType.Int).Value = userId; cmd.Parameters.Add("@TrustAccountLogDate2", SqlDbType.DateTime).Value =TrustAccountLogDate; // And then... reader = cmd.ExecuteReader(); if (reader.Read()) { double value = (double)reader.GetValue(0); if (System.Double.IsNaN(value)) return 0; else return value; } else return 0;

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  • Does Multiple NSURLConnection make delay of performance?

    - by oksk
    Hi all~. I made a multi files downloader. I implemented NSURLConnection using NSOperationQueue. NSOpetationQueue has many NSURLConnection operations. and, set MaxConcurrentOperationCount to 10. I thought my code is right, But after run the project, it was wrong. there are some connection error has occured. files url were right. and file download was completed. but downloading files, occur "timed out" error. It is so serious. I tested it with 8 files, and those total size is only 3M. But total download time is 2minutes ~!!! one file download spends only a few second. (2~3 s) but multi files download occur many overburden!! (2 minutes) I don't know why it is... Do Anyone know what reason is?

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  • Core Data performance deleteObject and save managed object context

    - by Gary
    I am trying to figure out the best way to bulk delete objects inside of my Core Data database. I have some objects with a parent/child relationship. At times I need to "refresh" the parent object by clearing out all of the existing children objects and adding new ones to Core Data. The 'delete all' portion of this operation is where I am running into trouble. I accomplish this by looping through the children and calling deleteObject for each one. I have noticed that after the NSManagedObjectContext:Save call following all of the deleteObject calls is very slow when I am deleting 15,000 objects. How can I speed up this call? Are there things happening during the save operation that I can be aware of and avoid by setting parameters different or setting up my model another way? I've noticed that memory spikes during this operation as well. I really just want to "delete * from". Thanks.

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  • Cisco 837 not passing UDP traffic properly (was: DNS query problem)

    - by TessellatingHeckler
    We have a setup of ADSL line - Cisco 837 ADSL router - Zyxel ZyWall 35 firewall/NAT - Switch - LAN. It has been fine for years, suddenly DNS resolution stopped working from the LAN to public DNS servers. No changes that I know of, so I can't revert anything. Current behaviour: DNS requests from the LAN using TCP show up in the oubound firewall log, in the Cisco debug log, in the dns-server-firewall, in tcpdump on the DNS server, the answer comes back, it works fine. DNS requests from the LAN using UDP show up in the outbound firewall log, in the Cisco debug log, but does NOT show in the dns-server-firewall, not in tcpdump on the DNS server, times out. DNS requests from the Cisco using UDP show up in the dns-server-firewall and in tcpdump on the DNS server, answer received, works fine. netcat connections to port 53 or a random port by TCP show up in the dns-server-firewall netcat connections to port 53 or a random port by UDP do not show up in the dns-server-firewall Summary: TCP seems fine throughought. UDP works from the Cisco over the ADSL, and it works from the LAN to the Cisco, but it doesn't seem to cross the Cisco 837 properly. Update: confirmed with netcat that any UDP traffic from the LAN is affected, not just traffic to port 53. Update: If I change the firewall's external IP to any other IP in the subnet, this starts working. When I put it back, it stops working. I now suspect it's an ISP issue (does that sound plausible?), and am removing the Cisco config.

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  • javamail vs sendmail performance during bulk email

    - by Glenn2041
    Hi all, I'm writing a Java mass emailer application to send out emails to send between 50,000 to 100,000 a day to users. The current plan is to delegate the sending to delegate to sendmail (on the local unix server). From our testing sendmail is sending a maximum of 5 emails per second. Would JavaMail be a faster option? Does anyone know what a faster way to send emails. We want to get this process out as quick as possible. Edit: BTW, a pdf will be attached too

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  • Asynchronous operations performance

    - by LicenseQ
    One of the features of asynchronous programming in .NET is saving threads during long running operation execution. The FileStream class can be setup to allow asynchronous operations, that allows running (e.g.) a copy operation without virtually using any threads. To my surprise, I found that running asynchronous stream copy performs not only slower, but also uses more processing power than synchronous stream copy equivalent. Is there any benchmark tests were done to compare a synchronous vs asynchronous operation execution (file, network, etc.)? Does it really make sense to perform an asynchronous operation instead of spanning separate thread and perform synchronous operation in server environment if the asynchronous operation is times slower than the synchronous one?

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  • glFramebufferTexture2D performance

    - by nornagon
    I'm doing heavy computation using the GPU, which involves a lot of render-to-texture operations. It's an iterative computation, so there's a lot of rendering to a texture, then rendering that texture to another texture, then rendering the second texture back to the first texture and so on, passing the texture through a shader each time. My question is: is it better to have a separate FBO for each texture I want to render into, or should I rather have one FBO and bind the target texture using glFramebufferTexture2D each time I want to change render target? My platform is OpenGL ES 2.0 on the iPhone.

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  • How to improve performance of Jquery autocomplete

    - by Bjorn
    Hi, i was planning to use jquery autocomplete for a site and have implemented a test version. Im now using an ajax call to retrieve a new list of strings for every character input. The problem is that it gets rather slow, 1.5s before the new list is populated. What is the best way to make autocomplete fast? Im using cakephp and just doing a find and with a limit of 10 items. Cheers Bjorn

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  • How does mysql define DISTINCT() in reference documentation

    - by goran
    EDIT: This question is about finding definitive reference to MySQL syntax on SELECT modifying keywords and functions. /EDIT AFAIK SQL defines two uses of DISTINCT keywords - SELECT DISTINCT field... and SELECT COUNT(DISTINCT field) ... However in one of web applications that I administer I've noticed performance issues on queries like SELECT DISTINCT(field1), field2, field3 ... DISTINCT() on a single column makes no sense and I am almost sure it is interpreted as SELECT DISTINCT field1, field2, field3 ... but how can I prove this? I've searched mysql site for a reference on this particular syntax, but could not find any. Does anyone have a link to definition of DISTINCT() in mysql or knows about other authoritative source on this? Best EDIT After asking the same question on mysql forums I learned that while parsing the SQL mysql does not care about whitespace between functions and column names (but I am still missing a reference). As it seems you can have whitespace between functions and the parenthesis SELECT LEFT (field1,1), field2... and get mysql to understand it as SELECT LEFT(field,1) Similarly SELECT DISTINCT(field1), field2... seems to get decomposed to SELECT DISTINCT (field1), field2... and then DISTINCT is taken not as some undefined (or undocumented) function, but as SELECT modifying keyword and the parenthesis around field1 are evaluated as if they were part of field expression. It would be great if someone would have a pointer to documentation where it is stated that the whitespace between functions and parenthesis is not significant or to provide links to apropriate MySQL forums, mailing lists where I could raise a question to put this into reference. EDIT I have found a reference to server option IGNORE SPACE. It states that "The IGNORE SPACE SQL mode can be used to modify how the parser treats function names that are whitespace-sensitive", later on it states that recent versions of mysql have reduced this number from 200 to 30. One of the remaining 30 is COUNT for example. With IGNORE SPACE enabled both SELECT COUNT(*) FROM mytable; SELECT COUNT (*) FROM mytable; are legal. So if this is an exception, I am left to conclude that normally functions ignore space by default. If functions ignore space by default then if the context is ambiguous, such as for the first function on a first item of the select expression, then they are not distinguishable from keywords and the error can not be thrown and MySQL must accept them as keywords. Still, my conclusions feel like they have lot of assumptions, I would still be grateful and accept any pointers to see where to follow up on this.

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  • Spikes in Socket Performance

    - by Harun Prasad
    We are facing random spikes in high throughput transaction processing system using sockets for IPC. Below is the setup used for the run: The client opens and closes new connection for every transaction, and there are 4 exchanges between the server and the client. We have disabled the TIME_WAIT, by setting the socket linger (SO_LINGER) option via getsockopt as we thought that the spikes were caused due to the sockets waiting in TIME_WAIT. There is no processing done for the transaction. Only messages are passed. OS used Centos 5.4 The average round trip time is around 3 milli seconds, but some times the round trip time ranges from 100 milli seconds to couple of seconds. Steps used for Execution and Measurement and output Starting the server $ python sockServerLinger.py /dev/null & Starting the client to post 1 million transactions to the server. And logs the time for a transaction in the client.log file. $ python sockClient.py 1000000 client.log Once the execution finishes the following command will show the execution time greater than 100 milliseconds in the format <line_number>:<execution_time>. $ grep -n "0.[1-9]" client.log | less Below is the example code for Server and Client. Server # File: sockServerLinger.py import socket, traceback,time import struct host = '' port = 9999 l_onoff = 1 l_linger = 0 lingeropt = struct.pack('ii', l_onoff, l_linger) s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER, lingeropt) s.bind((host, port)) s.listen(1) while 1: try: clientsock, clientaddr = s.accept() print "Got connection from", clientsock.getpeername() data = clientsock.recv(1024*1024*10) #print "asdasd",data numsent=clientsock.send(data) data1 = clientsock.recv(1024*1024*10) numsent=clientsock.send(data) ret = 1 while(ret>0): data1 = clientsock.recv(1024*1024*10) ret = len(data) clientsock.close() except KeyboardInterrupt: raise except: print traceback.print_exc() continue Client # File: sockClient.py import socket, traceback,sys import time i = 0 while 1: try: st = time.time() s = socket.socket(socket.AF_INET,socket.SOCK_STREAM) while (s.connect_ex(('127.0.0.1',9999)) != 0): continue numsent=s.send("asd"*1000) response = s.recv(6000) numsent=s.send("asd"*1000) response = s.recv(6000) i+=1 if i == int(sys.argv[1]): break except KeyboardInterrupt: raise except: print "in exec:::::::::::::",traceback.print_exc() continue print time.time() -st

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  • Retrieving varbinary output from a query in sql server into classic ASP

    - by user303526
    Hi, I'm trying to retrieve a varbinary output value from a query running on SQL Server 2005 into Classic ASP. The ASP execution just fails when it comes to part of code that is simply taking a varbinary output into a string. So I guess we gotta handle it some other way. Actually, I'm trying to set (sp_setapprole) and unset (sp_unsetapprole) application roles for a database connection. First I'd set the approle, then I'd run my required queries and finally unset the approle. During unsetting is when I need the cookie (varbinary) value in my ASP code so that I can create a query like 'exec sp_unsetapprole @cookie'. Well at this stage, I don't have the cookie (varbinary) value. The reason I'm doing this is I used to get 'sp_setapprole was not invoked correctly' error when trying to set app roles. I've disabled pooling by appending 'OLE DB Services = -2;Pooling=False' into my connection string. I know pooling helps performance wise but here I'm facing big problems. Please help me out to retrieve a varbinary value into an classic ASP file or suggest a way to set & unset app roles. Either way solutions are appreciated. Thanks, Nandagopal

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  • Fact or fiction: Webkit’s rendering performance is much lower when used in Qt

    - by Jen
    Using Qt’s Webkit implementation renders much slower than directly implementing the Webkit engine -- is this true or just a myth? From my own experience, I found the load time of a complex page about twice as long in Qt’s “Fancy Browser” example as it does in Google Chrome (which also incorporates a port of Webkit), but I hardly think that is a fair comparison. Any insights on this?

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  • Call to undefined function query() - using PDO in PHP

    - by webworm
    I have a written a script in PHP that reads from data from a MySQL database. I am new to PHP and I have been using the PDO library. I have been developing on a Windows machine using the WAMP Server 2 and all has been working well. However, when I uploaded my script to the LINUX server where it will be used I get the following error when I run my script. Fatal error: Call to undefined function query() This is the line where the error is occuring ... foreach($dbconn->query($sql) as $row) The variable $dbconn is first defined in my dblogin.php include file which I am listing below. <?php // Login info for the database $db_hostname = 'localhost'; $db_database = 'MY_DATABASE_NAME'; $db_username = 'MY_DATABASE_USER'; $db_password = 'MY_DATABASE_PASSWORD'; $dsn = 'mysql:host=' . $db_hostname . ';dbname=' . $db_database . ';'; try { $dbconn = new PDO($dsn, $db_username, $db_password); $dbconn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch (PDOException $e) { echo 'Error connecting to database: ' . $e->getMessage(); } ?> Inside the function where the error occurs I have the database connection defined as a superglobal as such ... global $dbconn; I am a bit confused as to what is happening since all worked well on my development machine. I was wondering if the PDO library was installed but from what I thought it was installed by default as part of PHP v5. The script is running on an Ubuntu (5.0.51a-3ubuntu5.4) machine and the PHP version is 5.2.4. Thank you for any suggestions. I am really lost on this.

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  • Help with JPQL query

    - by Robert
    I have to query a Message that is in a provided list of Groups and has not been Deactivated by the current user. Here is some pseudo code to illustrate the properties and entities: class Message { private int messageId; private String messageText; } class Group { private String groupId; private int messageId; } class Deactivated { private String userId; private int messageId; } Here is an idea of what I need to query for, it's the last AND clause that I don't know how to do (I made up the compound NOT IN expression). Filtering the deactivated messages by userId can result in multiple messageIds, how can I check if that subset of rows does not contain the messageId? SELECT msg FROM Message msg, Group group, Deactivated unactive WHERE group.messageId = msg.messageId AND (group.groupId = 'groupA' OR group.groupId = 'groupB' OR ...) AND ('someUserId', msg.messageId) NOT IN (unactive.userId, unactive.messageId) I don't know the number of groupIds ahead of time -- I receive them as a Collection<String> so I'll need to traverse them and add them to the JPQL dynamically.

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  • Command line tool to query HTML elements (linux)

    - by ipsec
    I am looking for a (linux) command line tool to parse HTML files and extract some elements, ideally with some XPath-like syntax. I have the following requirements: It must be able to parse arbitrary HTML files (which may contain errors) in a robust manner It must be able to extract text of elements and attributes What I have tried so far: xmlstarlet: would be perfect, but mostly reports errors in files (e.g. entity not defined), even xml fo or htmltidy does not help. xmllint: the best I have found so far, but is not able to extract attribute texts. Something like //a/@href reports <a href="foo">, what I need is just foo. string(//a/@href) works, but queries only the first entry. data is not supported. hxextract: works, but cannot extract attributes. XQilla: would support XPath 2.0 and thus data. It also support xqilla:parse-html, but I have had no luck making this work. Can you recommend me another tool?

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  • performance of linq extension method ElementAt

    - by Fabiano
    Hi The MSDN library entry to Enumerable.ElementAt(TSource) Method says "If the type of source implements IList, that implementation is used to obtain the element at the specified index. Otherwise, this method obtains the specified element." Let's say we have following example: ICollection<int> col = new List<int>() { /* fill with items */ }; IList<int> list = new List<int>() { /* fill with items */ }; col.ElementAt(10000000); list.ElementAt(10000000); Is there any difference in execution? or does ElementAt recognize that col also implements IList< although it's only declared as ICollection<? Thanks

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  • Performance of std::pow - cache misses???

    - by Eamon Nerbonne
    I've been trying to optimize a numeric program of mine, and have run into something of a mystery. I'm looping over code that performs thousands of floating point operations, and just 1 call to pow nevertheless, that call takes 5% of the time... That's not necessarily a critical issue, but it is odd, so I'd like to understand what's happening. When I profiled for cache misses, VS.NET 2010RC's profiler reports that virtually all cache misses are occurring in std::pow... so... what's up with that? Is there a faster alternative? I tried powf, but that's only slightly faster; it's still responsible for an abnormal number of cache misses. Why would a basic function like pow cause cache-misses?

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