Search Results

Search found 20904 results on 837 pages for 'disk performance'.

Page 743/837 | < Previous Page | 739 740 741 742 743 744 745 746 747 748 749 750  | Next Page >

• Force creation of query execution plan

  - by Marc

  I have the following situation: .net 3.5 WinForm client app accessing SQL Server 2008 Some queries returning relatively big amount of data are used quite often by a form Users are using local SQL Express and restarting their machines at least daily Other users are working remotely over slow network connections The problem is that after a restart, the first time users open this form the queries are extremely slow and take more or less 15s on a fast machine to execute. Afterwards the same queries take only 3s. Of course this comes from the fact that no data is cached and must be loaded from disk first. My question: Would it be possible to force the loading of the required data in advance into SQL Server cache? Note My first idea was to execute the queries in a background worker when the application starts, so that when the user starts the form the queries will already be cached and execute fast directly. I however don't want to load the result of the queries over to the client as some users are working remotely or have otherwise slow networks. So I thought just executing the queries from a stored procedure and putting the results into temporary tables so that nothing would be returned. Turned out that some of the result sets are using dynamic columns so I couldn't create the corresponding temp tables and thus this isn't a solution. Do you happen to have any other idea?

  Read the article

• Load Images in WPF application

  - by LLS

  I am not familiar with WPF, and I just feel quite confusing. I am trying to create a little computer game, and there are elements I want to display dynamically. I use Image class and add the images to a canvas. But I'm not sure whether it's a good practice. I feel that adding controls to canvas seem to be a little wired. And I'm a little concerned about the performance, because I may need many images. The real problem is, I can't load the images from the image files. I see an example in a text book like this (XMAL): <Image Panel.ZIndex="0" Margin="0,0,0,0" Name ="image1"> <Image.Source> <BitmapImage UriSource="Bell.gif" /> </Image.Source> </Image> Where Bell.gif is added into the project. And I tried to copy this in code to create an image. new Image { Source = new BitmapImage(new Uri("Blockade.bmp"))} But I got invalid Uri exception. After some search in the Internet, I found that loading resources dynamically seems to be difficult. Can I load the files added to the project dynamically? If I use absolute path then it's OK. But I can't expect every computer will put the files in the same location. Can I use relative path? I tried new Image { Source = new BitmapImage(new Uri(@"Pictures\Blank Land.bmp", UriKind.Relative)) } But it doesn't work. (The image is blank) Thanks.

  Read the article

• What file format can represent an uncompressed raster image at 48 or 64 bits per pixel?

  - by finnw

  I am creating screenshots under Windows and using the LockBits function from GDI+ to extract the pixel data, which will then be written to a file. To maximise performance I am also: Using the same PixelFormat as the source bitmap, to avoid format conversion Using the ImageLockModeUserInputBuf flag to extract the pixel data into a pre-allocated buffer This pre-allocated buffer (pointed to by BitmapData::Scan0) is part of a memory-mapped file (to avoid copying the pixel data again.) I will also be writing the code that reads the file, so I can use (or invent) any format I wish. However I would prefer to use a well-known format that existing programs (ideally web browsers) are able to read, because that means I can visually confirm that the images are correct before writing the code for the other program (that reads the image.) I have implemented this successfully for the PixelFormat32bppRGB format, which matches the format of a 32bpp BMP file, so if I extract the pixel data directly into the memory-mapped BMP file and prefix it with a BMP header I get a valid BMP image file that can be opened in Paint and most browsers. Unfortunately one of the machines I am testing on returns pixels in PixelFormat64bppPARGB format (presumably this is influenced by the video adapter driver) and there is no corresponding BMP pixel format for this. Converting to a 16, 24 or 32bpp BMP format slows the program down considerably (as well as being lossy) so I am looking for a file format that can use this pixel format without conversion, so I can extract directly into the memory-mapped file as I have done with the 32bpp format. What raster image file formats support 48bpp and/or 64bpp?

  Read the article

• Python: How to execute a SQL file or command

  - by Mestika

  Hi, I have this Python script: import sys import getopt import timeit import random import os import re import ibm_db import time from string import maketrans runs=5 queries=50 file = open("results.txt", "a") for r in range(5): print "Run %s\n" % r os.system("python reads.py -r1 -pquery1.sql -q50 -sespec") file.write('END QUERY READ 01') file.close() os.system("python query_read_02.py") Everything here is working, it is creating the results.txt file, it run the os.system("python reads.py...") file and that file is doing everything it's suppose to, but the problem comes when go and run the query_read_02.py file. In this file, it should execute a SQL command or a SQL file on my database, so I can create an index and see what the performance of that input is, but how do i do it? I create the connection to the database in the reads.py file, but it's hard to create the queries in there because I doesn't keep track of which file it has reached, it just execute commands from what the parameters are. I hope I've explained myself clear enough, otherwise please let me know. I just want to execute a SQL command or file which each query_read_0x.py file. Sincerely Mestika

  Read the article

• Why not systematically attach event in WPF instead of using delegate ?

  - by user310291

  For a button to handle event, we can add a delegate to the click property of the button: this.button1.Click += new System.EventHandler(this.button1_Click); But in WPF contrary to Winform, you can also attach a handler http://msdn.microsoft.com/en-us/magazine/cc785480.aspx So why not do so for the button ? Is performance better in first case maybe ? Update: I mean this Attached Events In order to enable elements to handle events that are declared in a different element, WPF supports something called attached events. Attached events are routed events that support a hookup in XAML on elements other than the type on which the event is declared. For example, if you want the Grid element to listen for a Button.Click event to bubble past, you would simply hook it up like the following: <Grid Button.Click="myButton_Click"> <Button Name="myButton" >Click Me</Button> </Grid> The resulting code in the compile-time-generated partial class now looks like this: #line 5 "..\..\Window1.xaml" ((System.Windows.Controls.Grid)(target)).AddHandler( System.Windows.Controls.Primitives.ButtonBase.ClickEvent, new System.Windows.RoutedEventHandler(this.myButton_Click));

  Read the article

• SQLite on iPhone - Techniques for tracking down multithreading-related bugs

  - by Jasarien

  Hey guys, I'm working with an Objective-C wrapper around SQLite that I didn't write, and documentation is sparse... It's not FMDB. The people writing this wrapper weren't aware of FMDB when writing this code. It seems that the code is suffering from a bug where database connections are being accessed from multiple threads -- which according to the SQLite documentation won't work if the if SQLite is compiled with SQLITE_THREADSAFE 2. I have tested the libsqlite3.dylib provided as part of the iPhone SDK and seen that it is compiled in this manner, using the sqlite_threadsafe() routine. Using the provided sqlite library, the code regularly hits SQLITE_BUSY and SQLITE_LOCKED return codes when performing routines. To combat this, I added some code to wait a couple of milliseconds and try again, with a maximum retry count of 50. The code didn't contain any retry logic prior to this. Now when a sqlite call returns SQLITE_BUSY or SQLITE_LOCKED, the retry loop is invoked and the retry returns SQLITE_MISUSE. Not good. Grasping at straws, I replaced the provided sqlite library with a version compiled by myself setting SQLITE_THREADSAFE to 1 - which according to the documentation means sqlite is safe to be used in a multithreaded environment, effectively serialising all of the operations. It incurs a performance hit, that which I haven't measured, but it ridded the app of the SQLITE_MISUSE happening and seemed to not need the retry logic as it never hit a busy or locked state. What I would rather do is fix the problem of accessing a single db connection from multiple threads, but I can't for the life of me find where it's occurring. So if anyone has any tips on locating multithreaded bugs I would be extremely appreciative. Thanks in advance.

  Read the article

• Access SSAS cube from across domains without direct database connection

  - by SuperKing

  Hello, I'm working with SQL Server Analysis Services for the first time and have the dilemma of working on a project in which users must be able to access SSAS Cubes (via a custom web dashboard) that live across different servers and domains, but without having access to the other server's SSAS database connection strings. So Organization A and Organization B will have their own cubes on their own servers, but Organization A users must be able to view Organization B's cubes, and Organization B users must be able to view Organization A's cubes, but neither organization should have access to the connection string. I've read about allowing HTTP access to the SSAS server and cube from the link below, but that requires setting up users for authentication or allowing anonymous access to one organization's server for users of another organization, and I'm not sure this would be acceptable for this situation, or if this is the preferred way to do this. Is performance acceptable here? http://technet.microsoft.com/en-us/library/cc917711.aspx I also wonder if perhaps it makes sense to run a nightly/weekly process that accesses the other organization's SSAS database via a web service or something, and pull that data into a database on the organization's server, and then rebuild the cube. Then that cube would be queried without having to go and connect to the other organization server when viewing the cube. Has anyone else attempted to accomplish something similar? Is HTTP access the standard way to go for this? Or any other possible options? Thanks, and please let me know if you need more info, still unclear on how some of this works.

  Read the article

• can't write to physical drive in win 7??

  - by matt

  I wrote a disk utility that allowed you to erase whole physical drives. it uses the windows file api, calling : destFile = CreateFile("\\.\PhysicalDrive1", GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,createflags, NULL); and then just calling WriteFile, and making sure you write in multiples of sectors, i.e. 512 bytes. this worked fine in the past, on XP, and even on the Win7 RC, all you have to do is make sure you are running it as an administrator. but now I have retail Win7 professional, it doesn't work anymore! the drives still open fine for writing, but calling WriteFile on the successfully opened Drive now fails! does anyone know why this might be? could it have something to do with opening it with shared flags? this is always what I have done before, and its worked. could it be that something is now sharing the drive? blocking the writes? is there some way to properly "unmount" A drive, or atleast the partitions on it so that I would have exclusive access to it? some other tools that used to work don't any more either, but some do, like the WD Diagnostic's erase functionality. and after it has erased the drive, my tool then works on it too! leading me to belive there is some "unmount" process I need to be doing to the drive first, to free up permission to write to it. Any ideas?

  Read the article

• Throttling outbound API calls generated by a Rails app

  - by Sharpie

  I am not a professional web developer, but I like to wrench on websites as a hobby. Recently, I have been playing with developing a Rails app as a project to help me learn the framework. The goal of my toy app is to harvest data from another service through their API and make it available for me to query using a search function. However, the service I want to pull data from imposes a rate limit on the number of API calls that may be executed per minute. I plan on having my app run a daily update which may generate a burst of API calls that far exceeds the limit provided by the external service. I wish to respect the performance of the external site and so would like to throttle the rate at which my app executes the calls. I have done a little bit of searching and the overwhelming amount of tutorial material and pre-built libraries I have found cover throttling inbound API calls to a web app and I can find little discussion of controlling the flow of outbound calls. Being both an amateur web developer and a rails newbie, it is entirely possible that I have been executing the wrong searches in the wrong places. Therefore my questions are: Is there a nice website out there aggregating Rails tutorials that has material related to throttling outbound API requests? Are there any ruby gems or other libraries that would help me throttle the requests? I have some ideas of how I might go about writing a throttling system using a queue-based worker like DelayedJob or Resque to manage the API calls, but I would rather spend my weekends building the rest of the site if there is a good pre-built solution out there already.

  Read the article

• Linux Lightweight Distro and X Windows for Development

  - by Fernando Barrocal

  Heyall... I want to build a lightweight linux configuration to use for development. The first idea is to use it inside a Virtual Machine under Windows, or old Laptops with 1Gb RAM top. Maybe even a distributable environment for developers. So the whole idea is to use a LAMP server, Java Application Server (Tomcat or Jetty) and X Windows (any Window manager, from FVWM to Enlightment), Eclipse, maybe jEdit and of course Firefox. Edit: I am changing this post to compile a possible list of distros and window managers that can be used to configure a real lightweight development environment. I am using as base personal experiences on this matter. Info about the distros can be easily found in their sites. So please, focus on personal use of those systems Distros Ubuntu / Xubuntu Pros: Personal Experience in old systems or low RAM environment - @Schroeder, @SCdF Several sugestions based on personal knowledge - @Kyle, @Peter Hoffmann Gentoo Pros: Not targeted to Desktop Users - @paan Don't come with a huge ammount of applications - @paan Slackware Pros: Suggested as best performance in a wise install/configuration - @Ryan Damn Small Linux Pros: Main focus is the lightweight factor - 50MB LiveCD - @Ryan Debian Pros: Very versatile, can be configured for both heavy and lightweight computers - @Ryan APT as package manager - @Kyle Based on compatibility and usability - @Kyle -- Fell Free to add Prós and Cons on this, so we can compile a good Reference. -- X Windows suggestion keep coming about XFCE. If others are to add here, open a session for it Like the distro one :)

  Read the article

• Seeking reporting or templating tool to generate large formatted PDF reports from dataset

  - by Mr. Tacos

  Say I have some data in MySQL or a big ole CSV file. I also have a report. It's a PDF, call it 100 pages long. I need to generate variations on this PDF for slices of the data. More specific example: I have a CSV file with each StackOverflow user in a row and each column contains various statistics about that user. I have a report called "Your StackOverflow Performance". Its got lots of text, always the same, but each section contains something like: "You Vs. The Average StackOverflow Poster on this metric". I want a table that appears there that has the average data, which is the same in every run of the PDF, in one column. In the second column, I want your data, which is different for each PDF/row in the CSV file/user of StackOverflow. I'm pretty sure people use things like Crystal for this? Is there something in MS SQL Server that's good for this? An open source template language? I'm not even really sure if what I need is called a 'reporting' tool (since I don't really need to do any crunching, the data in this case is being crunched by a series of scripts and SPSS, I don't need bands and subbands and so on) or 'templating'. Is there even such a thing as templating PDFs? Natch, I'd be fine with something that generates output easily scriptable to PDF, like eps, but not something like HTML. The report formatting is fussy and done and externally determined and handed down from on high. It's print-oriented, not webby. Thanks in advance.

  Read the article

• How to localize an app on Google App Engine?

  - by Petri Pennanen

  What options are there for localizing an app on Google App Engine? How do you do it using Webapp, Django, web2py or [insert framework here]. 1. Readable URLs and entity key names Readable URLs are good for usability and search engine optimization (Stack Overflow is a good example on how to do it). On Google App Engine, key based queries are recommended for performance reasons. It follows that it is good practice to use the entity key name in the URL, so that the entity can be fetched from the datastore as quickly as possible. Currently I use the function below to create key names: import re import unicodedata def urlify(unicode_string): """Translates latin1 unicode strings to url friendly ASCII. Converts accented latin1 characters to their non-accented ASCII counterparts, converts to lowercase, converts spaces to hyphens and removes all characters that are not alphanumeric ASCII. Arguments unicode_string: Unicode encoded string. Returns String consisting of alphanumeric (ASCII) characters and hyphens. """ str = unicodedata.normalize('NFKD', unicode_string).encode('ASCII', 'ignore') str = re.sub('[^\w\s-]', '', str).strip().lower() return re.sub('[-\s]+', '-', str) This works fine for English and Swedish, however it will fail for non-western scripts and remove letters from some western ones (like Norwegian and Danish with their œ and ø). Can anyone suggest a method that works with more languages? 2. Translating templates Does Django internationalization and localization work on Google App Engine? Are there any extra steps that must be performed? Is it possible to use Django i18n and l10n for Django templates while using Webapp? The Jinja2 template language provides integration with Babel. How well does this work, in your experience? What options are avilable for your chosen template language? 3. Translated datastore content When serving content from (or storing it to) the datastore: Is there a better way than getting the *accept_language* parameter from the HTTP request and matching this with a language property that you have set with each entity?

  Read the article

• Shared value in parallel python

  - by Jonathan

  Hey all- I'm using ParallelPython to develop a performance-critical script. I'd like to share one value between the 8 processes running on the system. Please excuse the trivial example but this illustrates my question. def findMin(listOfElements): for el in listOfElements: if el < min: min = el import pp min = 0 myList = range(100000) job_server = pp.Server() f1 = job_server.submit(findMin, myList[0:25000]) f2 = job_server.submit(findMin, myList[25000:50000]) f3 = job_server.submit(findMin, myList[50000:75000]) f4 = job_server.submit(findMin, myList[75000:100000]) The pp docs don't seem to describe a way to share data across processes. Is it possible? If so, is there a standard locking mechanism (like in the threading module) to confirm that only one update is done at a time? l = Lock() if(el < min): l.acquire if(el < min): min = el l.release I understand I could keep a local min and compare the 4 in the main thread once returned, but by sharing the value I can do some better pruning of my BFS binary tree and potentially save a lot of loop iterations. Thanks- Jonathan

  Read the article

• RHEL 5.3 Kickstart - How specify location of individual package in Workstation folder?

  - by Ed

  I keep getting "package does not exist" errors during the install. I made a kickstart ISO to create an unattended install of a RHEL 5.3 build machine for C++ software releases. It pulls the kickstart config file from our internal web server. This is handy; it makes it easy to test and modify without having to make a new ISO. And I plan to check it in to version control if I can get it working. Anyway, the rpm packages are located in two folders on the disk; Client and Workstation. The packages install fine for the ones that are physically located under the Client folder. It cannot find those under the Workstation folder such as as doxygen and subversion complaining that packages do not exist. Is there a way to specify the individual package location? # ----------------------------------------------------------------------------- # P A C K A G E S # ----------------------------------------------------------------------------- %packages @gnome-desktop @core @base @base-x @printing @development-tools emacs kexec-tools fipscheck xorg-x11-server-Xnest xorg-x11-server-Xvfb #Packages Located in Workstation Folder *** Install can not find any of these ?? bison doxygen gcc-c++ subversion zlib-devel freetype-devel libxml2-devel Thanks in advance, -Ed

  Read the article

• How to make xml in C#?

  - by kacalapy

  i have not worked with XML in a while can someone post the syntax needed to build and save an xml node structure that resembles that of a tree structure that is created by a recursive function. basically i have a recursive function that saves data found an a page(url) and then follows each URL found on that page recursivley and does the same to it. to audit this i want an output as a xml file to disk so i can see how it is doing its recursion and parsing. the code i have is below. please add to it the needed xml calls needed to create a xml structure like the one i show below. (please include the full name space so i can see where the objects i need in .net are for this.) page1.htm has 2 links on it: <a href=page1_1.htm> <a href=page1_2.htm> page1_1.htm has 2 links on it <a href=page1_1_a.htm> (this then will have some links also) <a href=page1_1_b.htm> (this then will have no more links on it - dead end) the xml should do something like this: <node url=page1.htm> ...<node url=page1_1_a.htm> ...... <node url="xxx.htm"/> ...... <node url="yyy.htm".> ... </node> ...<node url=page1_1_b.htm /> </node>

  Read the article

• update variable based upon results from .NET backgroundworker

  - by Bruce

  I've got a C# program that talks to an instrument (spectrum analyzer) over a network. I need to be able to change a large number of parameters in the instrument and read them back into my program. I want to use backgroundworker to do the actual talking to the instrument so that UI performance doesn't suffer. The way this works is - 1) send command to the instrument with new parameter value, 2) read parameter back from the instrument so I can see what actually happened (for example, I try to set the center frequency above the max that the instrument will handle and it tells me what it will actually handle), and 3) update a program variable with the actual value received from the instrument. Because there are quite a few parameters to be updated I'd like to use a generic routine. The part I can't seem to get my brain around is updating the variable in my code with what comes back from the instrument via backgroundworker. If I used a separate RunWorkerCompleted event for each parameter I could hardwire the update directly to the variable. I'd like to come up with a way of using a single routine that's capable of updating any of the variables. All I can come up with is passing a reference number (different for each parameter) and using a switch statement in the RunWorkerCompleted handler to direct the result. There has to be a better way.

  Read the article

• Does "for" in .Net Framework 4.0 execute loops in parallel? Or why is the total not the sum of the p

  - by Shiraz Bhaiji

  I am writing code to performance test a web site. I have the following code: string url = "http://xxxxxx"; System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch(); System.Diagnostics.Stopwatch totalTime = new System.Diagnostics.Stopwatch(); totalTime.Start(); for (int i = 0; i < 10; i++) { stopwatch.Start(); WebRequest request = HttpWebRequest.Create(url); WebResponse webResponse = request.GetResponse(); webResponse.Close(); stopwatch.Stop(); textBox1.Text += "Time Taken " + i.ToString() + " = " + stopwatch.Elapsed.Milliseconds.ToString() + Environment.NewLine; stopwatch.Reset(); } totalTime.Stop(); textBox1.Text += "Total Time Taken = " + totalTime.Elapsed.Milliseconds.ToString() + Environment.NewLine; Which is giving the following result: Time Taken 0 = 88 Time Taken 1 = 161 Time Taken 2 = 218 Time Taken 3 = 417 Time Taken 4 = 236 Time Taken 5 = 217 Time Taken 6 = 217 Time Taken 7 = 218 Time Taken 8 = 409 Time Taken 9 = 48 Total Time Taken = 257 I had expected the total time to be the sum of the individual times. Can anybody see why it is not?

  Read the article

• SQL Server - Multi-Column substring matching

  - by hamlin11

  One of my clients is hooked on multi-column substring matching. I understand that Contains and FreeText search for words (and at least in the case of Contains, word prefixes). However, based upon my understanding of this MSDN book, neither of these nor their variants are capable of searching substrings. I have used LIKE rather extensively (Select * from A where A.B Like '%substr%') Sample table A: ID | Col1 | Col2 | Col3 | ------------------------------------- 1 | oklahoma | colorado | Utah | 2 | arkansas | colorado | oklahoma | 3 | florida | michigan | florida | ------------------------------------- The following code will give us row 1 and row 2: select * from A where Col1 like '%klah%' or Col2 like '%klah%' or Col3 like '%klah%' This is rather ugly, probably slow, and I just don't like it very much. Probably because the implementations that I'm dealing with have 10+ columns that need searched. The following may be a slight improvement as code readability goes, but as far as performance, we're still in the same ball park. select * from A where (Col1 + ' ' + Col2 + ' ' + Col3) like '%klah%' I have thought about simply adding insert, update, and delete triggers that simply add the concatenated version of the above columns into a separate table that shadows this table. Sample Shadow_Table: ID | searchtext | --------------------------------- 1 | oklahoma colorado Utah | 2 | arkansas colorado oklahoma | 3 | florida michigan florida | --------------------------------- This would allow us to perform the following query to search for '%klah%' select * from Shadow_Table where searchtext like '%klah%' I really don't like having to remember that this shadow table exists and that I'm supposed to use it when I am performing multi-column substring matching, but it probably yields pretty quick reads at the expense of write and storage space. My gut feeling tells me there there is an existing solution built into SQL Server 2008. However, I don't seem to be able to find anything other than research papers on the subject. Any help would be appreciated.

  Read the article

• VB.net Saving an MetaFile / EMF as a bitmap ( .tiff)

  - by pehaada

  Currently I have a third party control that generates a Metafile. I can save the .wmf file to disk with out issue. The problem is how do I render the Metafile as a Tiff file. Currently I have the following code to get my metafile and save it. Dim mf As Metafile = page.GetImage(TXTextControl.Page.PageContent.All) Dim enhMetafileHandle As IntPtr = mf.GetHenhmetafile() Dim h As IntPtr Dim bufferSize As UInteger = GetEnhMetaFileBits(enhMetafileHandle, 0, h) Dim buffer(CInt(bufferSize)) As Byte GetEnhMetaFileBits(enhMetafileHandle, bufferSize, buffer) Dim msMetafileStream As New MemoryStream msMetafileStream.Write(buffer, 0, CInt(bufferSize)) Dim baMetafileData() As Byte baMetafileData = msMetafileStream.ToArray Dim g As Graphics = Graphics.FromImage(mf) mf.Dispose() File.WriteAllBytes("c:\a.wmf", baMetafileData) end sub _ Public Shared Function GetEnhMetaFileBits( ByVal hEMF As System.IntPtr, ByVal nSize As UInteger, ByVal lpData As IntPtr) As UInteger End Function <System.Runtime.InteropServices.DllImportAttribute("gdi32.dll", EntryPoint:="GetEnhMetaFileBits")> _ Public Shared Function GetEnhMetaFileBits(<System.Runtime.InteropServices.InAttribute()> ByVal hEMF As System.IntPtr, ByVal nSize As UInteger, ByVal lpData() As Byte) As UInteger End Function I've tried all sort of IMAGE and Graphic calls and just can't save the meta file as a .tiff. Any suggestions would be great. I even tried to create a new bitmap and draw the metafile onto it. I always end up with a GDI exception being thrown.

  Read the article

• When does it makes sense to use a map?

  - by kiwicptn

  I am trying to round up cases when it makes sense to use a map (set of key-value entries). So far I have five categories (see below). Assuming more exist, what are they? Please limit each answer to one unique category, put up an example, and vote up the fascinating ones. Property values (like a bean) age -> 30 sex -> male loc -> calgary Histograms peter -> 1 john -> 7 paul -> 5 Presence, with O(1) performance peter -> 1 john -> 1 paul -> 1 Functions peter -> treatPeter() john -> dealWithJohn() paul -> managePaul() Conversion peter -> pierre john -> jean paul -> paul

  Read the article

• GAE modeling relationship options

  - by Sway

  Hi there, I need to model the following situation and I can't seem to find a consistent example on how to do it "correctly" for the google app engine. Suppose I've got a simple situation like the following: [Company] 1 ----- M [Stare] A company has one to many stores. Each store has an address made up of a address line 1, city, state, country, postcode etc. Ok. Lets say we need to create say an "Audit". An Audit is for a company and can be across one to many stares. So something like: [Audit] 1 ------ 1 [Company] 1 ------ M [Store] Now we need to query all of the "audits" based on the Store "addresses" in order to send the "Auditors" to the right locations. There seem to be numerous articles like this one: http://code.google.com/appengine/articles/modeling.html Which give examples of creating a "ContactCompany" model class. However they also say that you should use this kind of relationship only when you "really need to" and with "care" for performance. I've also read - frequently - that you should denormalize as much as possible thereby moving all of the "query-able" data into the Audit class. So what would you suggest as the best way to solve this? I've seen that there is an Expando class but I'm not sure if that is the "best" option for this. Any help or thoughts on this would be totally appreciated. Thanks in advance, Matt

  Read the article

• SQL Server Search Proper Names Full Text Index vs LIKE + SOUNDEX

  - by Matthew Talbert

  I have a database of names of people that has (currently) 35 million rows. I need to know what is the best method for quickly searching these names. The current system (not designed by me), simply has the first and last name columns indexed and uses "LIKE" queries with the additional option of using SOUNDEX (though I'm not sure this is actually used much). Performance has always been a problem with this system, and so currently the searches are limited to 200 results (which still takes too long to run). So, I have a few questions: Does full text index work well for proper names? If so, what is the best way to query proper names? (CONTAINS, FREETEXT, etc) Is there some other system (like Lucene.net) that would be better? Just for reference, I'm using Fluent NHibernate for data access, so methods that work will with that will be preferred. I'm using SQL Server 2008 currently. EDIT I want to add that I'm very interested in solutions that will deal with things like commonly misspelled names, eg 'smythe', 'smith', as well as first names, eg 'tomas', 'thomas'. Query Plan |--Parallelism(Gather Streams) |--Nested Loops(Inner Join, OUTER REFERENCES:([testdb].[dbo].[Test].[Id], [Expr1004]) OPTIMIZED WITH UNORDERED PREFETCH) |--Hash Match(Inner Join, HASH:([testdb].[dbo].[Test].[Id])=([testdb].[dbo].[Test].[Id])) | |--Bitmap(HASH:([testdb].[dbo].[Test].[Id]), DEFINE:([Bitmap1003])) | | |--Parallelism(Repartition Streams, Hash Partitioning, PARTITION COLUMNS:([testdb].[dbo].[Test].[Id])) | | |--Index Seek(OBJECT:([testdb].[dbo].[Test].[IX_Test_LastName]), SEEK:([testdb].[dbo].[Test].[LastName] >= 'WHITDþ' AND [testdb].[dbo].[Test].[LastName] < 'WHITF'), WHERE:([testdb].[dbo].[Test].[LastName] like 'WHITE%') ORDERED FORWARD) | |--Parallelism(Repartition Streams, Hash Partitioning, PARTITION COLUMNS:([testdb].[dbo].[Test].[Id])) | |--Index Seek(OBJECT:([testdb].[dbo].[Test].[IX_Test_FirstName]), SEEK:([testdb].[dbo].[Test].[FirstName] >= 'THOMARþ' AND [testdb].[dbo].[Test].[FirstName] < 'THOMAT'), WHERE:([testdb].[dbo].[Test].[FirstName] like 'THOMAS%' AND PROBE([Bitmap1003],[testdb].[dbo].[Test].[Id],N'[IN ROW]')) ORDERED FORWARD) |--Clustered Index Seek(OBJECT:([testdb].[dbo].[Test].[PK__TEST__3214EC073B95D2F1]), SEEK:([testdb].[dbo].[Test].[Id]=[testdb].[dbo].[Test].[Id]) LOOKUP ORDERED FORWARD) SQL for above: SELECT * FROM testdb.dbo.Test WHERE LastName LIKE 'WHITE%' AND FirstName LIKE 'THOMAS%' Based on advice from Mitch, I created an index like this: CREATE INDEX IX_Test_Name_DOB ON Test (LastName ASC, FirstName ASC, BirthDate ASC) INCLUDE (and here I list the other columns) My searches are now incredibly fast for my typical search (last, first, and birth date).

  Read the article

• Maintain denormalized data with NHibernate EventListener

  - by Michael Valenty

  I have one bit of denormalized data used for performance reasons and I'm trying to maintain the data with an NHibernate event listener rather than a trigger. I'm not convinced this is the best approach, but I'm neck deep into it and I want to figure this out before moving on. I'm getting following error: System.InvalidOperationException : Collection was modified; enumeration operation may not execute. System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource) System.Collections.Generic.List`1.Enumerator.MoveNextRare() System.Collections.Generic.List`1.Enumerator.MoveNext() NHibernate.Engine.ActionQueue.ExecuteActions(IList list) NHibernate.Engine.ActionQueue.ExecuteActions() NHibernate.Event.Default.AbstractFlushingEventListener.PerformExecutions (IEventSource session) NHibernate.Event.Default.DefaultFlushEventListener.OnFlush(FlushEvent event) NHibernate.Impl.SessionImpl.Flush() NHibernate.Transaction.AdoTransaction.Commit() Here's the code to make happen: using (var tx = session.BeginTransaction()) { var business = session .Get<Business>(1234) .ChangeZipCodeTo("92011"); session.Update(business); tx.Commit(); // error happens here } and the event listener: public void OnPostUpdate(PostUpdateEvent @event) { var business = @event.Entity as Business; if (business != null) { var links = @event.Session .CreateQuery("select l from BusinessCategoryLink as l where l.Business.BusinessId = :businessId") .SetParameter("businessId", business.BusinessId) .List<BusinessCategoryLink>(); foreach (var link in links) { link.Location = business.Location; @event.Session.Update(link); } } }

  Read the article

• Sorting GridView Formed With Data Set

  - by nani

  Following Code is for Sorting GridView Formed With DataSet Source: http://www.highoncoding.com/Articles/176_Sorting_GridView_Manually_.aspx But it is not displaying any output. There is no problem in sql connection. I am unable to trace the error, please help me. Thank You. public partial class _Default : System.Web.UI.Page { private const string ASCENDING = " ASC"; private const string DESCENDING = " DESC"; private DataSet GetData() { SqlConnection cnn = new SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;"); SqlDataAdapter da = new SqlDataAdapter("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", cnn); DataSet ds = new DataSet(); da.Fill(ds); return ds; } public SortDirection GridViewSortDirection { get { if (ViewState["sortDirection"] == null) ViewState["sortDirection"] = SortDirection.Ascending; return (SortDirection)ViewState["sortDirection"]; } set { ViewState["sortDirection"] = value; } } protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) { string sortExpression = e.SortExpression; if (GridViewSortDirection == SortDirection.Ascending) { GridViewSortDirection = SortDirection.Descending; SortGridView(sortExpression, DESCENDING); } else { GridViewSortDirection = SortDirection.Ascending; SortGridView(sortExpression, ASCENDING); } } private void SortGridView(string sortExpression, string direction) { // You can cache the DataTable for improving performance DataTable dt = GetData().Tables[0]; DataView dv = new DataView(dt); dv.Sort = sortExpression + direction; GridView1.DataSource = dv; GridView1.DataBind(); } } aspx page asp:GridView ID="GridView1" runat="server" AllowSorting="True" OnSorting="GridView1_Sorting" /asp:GridView

  Read the article

• Changing customErrors in web.config semi-dynamically

  - by Tom Ritter

  The basic idea is we have a test enviroment which mimics Production so customErrors="RemoteOnly". We just built a test harness that runs against the Test enviroment and detects breaks. We would like it to be able to pull back the detailed error. But we don't want to turn customErrors="On" because then it doesn't mimic Production. I've looked around and thought a lot, and everything I've come up with isn't possible. Am I wrong about any of these points? We can't turn customErrors on at runtime because when you call configuration.Save() - it writes the web.config to disk and now it's Off for every request. We can't symlink the files into a new top level directory with it's own web.config because we're on windows and subversion on windows doesn't do symlinks. We can't use URL-Mapping to make an empty folder dir2 with its own web.config and make the files in dir1 appear to be in dir2 - the web.config doesn't apply We can't copy all the aspx files into dir2 with it's own web.config because none of the links would be consistent and it's a horrible hacky solution. We can't change customErrors in web.config based on hostname (e.g. add another dns entry to the test server) because it's not possible/supported We can't do any virtual directory shenanigans to make it work. If I'm not, is there a way to accomplish what I'm trying to do? Turn on customErrors site-wide under certain circumstances (dns name or even a querystring value)?

  Read the article

< Previous Page | 739 740 741 742 743 744 745 746 747 748 749 750  | Next Page >