Search Results

Search found 40870 results on 1635 pages for 'database design'.

Page 290/1635 | < Previous Page | 286 287 288 289 290 291 292 293 294 295 296 297  | Next Page >

  • Nested Data XML design

    - by esryl
    Looking to nest (to unlimited levels) elements in XML. Like so: <items> <item> <name>Item One</name> <item> <name>Item Two</name> </item> <item> <name>Item Three</name> <item> <name>Item Four</name> </item> <!-- etc... --> </item> </item> </items> However. While browsing for a solution I noticed in the comments of: http://stackoverflow.com/questions/988139/weird-nesting-in-xml while the above is well formed it would not validate against any sinsible DTD. Two things, what is a better way of nesting similar elements, and secondly what would be the design of the DTD. UPDATE: Would prefer to validate against an XML Schema rather than DTD.

    Read the article

  • Load some data from database and hide it somewhere in a web page

    - by kwokwai
    Hi all, I am trying to load some data (which may be up to a few thousands words) from the database, and store the data somewhere in a html web page for comparing the data input by users. I am thinking to load the data to a Textarea under Div tag and hide the the data: <Div id="reference" style="Display:none;"> <textarea rows="2" cols="20" id="database"> html, htm, php, asp, jsp, aspx, ctp, thtml, xml, xsl... </textarea> </Div> <table border=0 width="100%"> <tr> <td>Username</td> <td> <div id="username"> <input type="text" name="data" id="data"> </div> </td> </tr> </table> <script> $(document).ready(function(){ //comparing the data loaded from database with the user's input if($("#data").val()==$("#database").val()) {alert("error");} }); </script> I am not sure if this is the best way to do it, so could you give me some advice and suggest your methods please.

    Read the article

  • Threadpool design question

    - by ZeroVector
    I have a design question. I want some feedback to know if a ThreadPool is appropriate for the client program I am writing. I am having a client running as a service processing database records. Each of these records contains connection information to external FTP sites [basically it is a queue of files to transfer]. A lot of them are to the same host, just moving different files. Therefore, I am grouping them together by host. I want to be able to create a new thread per host. I really don't care when the transfers finish, they just need to do all the work (or try to do) they were assigned, and then terminate once they are finished, cleaning up all resources they used in the process. I anticipate no more than 10-25 connections to be established. Once the transfer queue is empty, the program will simply wait until there are records in the queue again. Is the ThreadPool a good candidate for this or should I use a different approach? Edit: For the most part, this is the only significant custom application running on the server.

    Read the article

  • Proper API Design for Version Independence?

    - by Justavian
    I've inherited an enormous .NET solution of about 200 projects. There are now some developers who wish to start adding their own components into our application, which will require that we begin exposing functionality via an API. The major problem with that, of course, is that the solution we've got on our hands contains such a spider web of dependencies that we have to be careful to avoid sabotaging the API every time there's a minor change somewhere in the app. We'd also like to be able to incrementally expose new functionality without destroying any previous third party apps. I have a way to solve this problem, but i'm not sure it's the ideal way - i was looking for other ideas. My plan would be to essentially have three dlls. APIServer_1_0.dll - this would be the dll with all of the dependencies. APIClient_1_0.dll - this would be the dll our developers would actual refer to. No references to any of the mess in our solution. APISupport_1_0.dll - this would contain the interfaces which would allow the client piece to dynamically load the "server" component and perform whatever functions are required. Both of the above dlls would depend upon this. It would be the only dll that the "client" piece refers to. I initially arrived at this design, because the way in which we do inter process communication between windows services is sort of similar (except that the client talks to the server via named pipes, rather than dynamically loading dlls). While i'm fairly certain i can make this work, i'm curious to know if there are better ways to accomplish the same task.

    Read the article

  • Factorial function - design and test.

    - by lukas
    I'm trying to nail down some interview questions, so I stared with a simple one. Design the factorial function. This function is a leaf (no dependencies - easly testable), so I made it static inside the helper class. public static class MathHelper { public static int Factorial(int n) { Debug.Assert(n >= 0); if (n < 0) { throw new ArgumentException("n cannot be lower that 0"); } Debug.Assert(n <= 12); if (n > 12) { throw new OverflowException("Overflow occurs above 12 factorial"); } //by definition if (n == 0) { return 1; } int factorialOfN = 1; for (int i = 1; i <= n; ++i) { //checked //{ factorialOfN *= i; //} } return factorialOfN; } } Testing: [TestMethod] [ExpectedException(typeof(OverflowException))] public void Overflow() { int temp = FactorialHelper.MathHelper.Factorial(40); } [TestMethod] public void ZeroTest() { int factorialOfZero = FactorialHelper.MathHelper.Factorial(0); Assert.AreEqual(1, factorialOfZero); } [TestMethod] public void FactorialOf5() { int factOf5 = FactorialHelper.MathHelper.Factorial(5); Assert.AreEqual(120,factOf5); } [TestMethod] [ExpectedException(typeof(ArgumentException))] public void NegativeTest() { int factOfMinus5 = FactorialHelper.MathHelper.Factorial(-5); } I have a few questions: Is it correct? (I hope so ;) ) Does it throw right exceptions? Should I use checked context or this trick ( n 12 ) is ok? Is it better to use uint istead of checking for negative values? Future improving: Overload for long, decimal, BigInteger or maybe generic method? Thank you

    Read the article

  • C++ AI Design Question

    - by disney
    Hi, I am currently writing a bot for a MMORPG. Though, currently I am stuck at trying to figure out how to nicely implement this. The design problem is related to casting the character spells in the correct order. Here is a simple example to what I need to archieve. It's not related to casting them, but doing it in the correct order. I would know how simply cast them randomly, by checking which skill has not yet been casted, but in right order as being shown in the GUI, not really. note: the skill amount may differ, it's not always 3, maximum 10 though. Charactername < foobar has 3 skills. Skill 1: Name ( random1 ) cooldown ( 1000 ms ) cast duration ( 500 ms ) Skill 2: Name ( random2 ) cooldown ( 1500 ms ) cast duration ( 700 ms ) Skill 3: Name ( random3 ) cooldown ( 2000 ms ) cast duration ( 900 ms ) I don't really know how I could implement this, if anyone has some thoughts, feel free to share. I do know that most of the people don't like the idea of cheating in games, I don't like it either, nor I am actually playing the game, but its an interesting field for me. Thank you.

    Read the article

  • Beginner PHP: I can't insert data into MYSQL database

    - by Victor
    I'm learning PHP right now and I'm trying to insert data into a MySQL database called "pumpl2" The table is set up like this. create table product ( productid int unsigned not null auto_increment primary key, price int(9) not null, value int(9) not null, description text ); I have a form and want to insert the fields from the form in the database. Here is what the php file looks like. <?php // create short variable names $price = $_POST['price']; $value = $_POST['value']; $description = $_POST['description']; if (!$price || !$value || !$description) { echo "You have not entered all the required details.<br />" ."Please go back and try again."; exit; } @ $db = new mysqli('localhost', 'pumpl', '********', 'pumpl2'); if (mysqli_connect_errno()) { echo "Error: Could not connect to database. Please try again later."; exit; } $query = "insert into pumpl2 values ('".$price."', '".$value."', '".$description."')"; $result = $db->query($query); if ($result) { echo $db->affected_rows." product inserted into database."; } else { echo "An error has occurred. The item was not added."; } $db->close(); ?> When I submit the form, I get an error message "An error has occurred. The item was not added." Does anyone know what the problem is? Thank you!

    Read the article

  • MVC design for archived data view

    - by Hemant Tank
    Implementation of a standard archive process in ASP.Net MVC. Backend SQL Server 2005 We've an existing web app built in MVC. We've an Entity "Claim" and it has some child entities like ClaimDetails, Files, etc... A pretty standard setup in DB. Each entity has its own table and are linked via FK. Now, we need to have an "Archive" feature in web app which will allow admin to archive a Claim and its child entities. An archived Claim shud become readonly when visited again. Here're some points on which I need your valued opinion - To keep it simple and scalable (for a few million records) for now we plan to simply add a bit field "Archived" to the Claim table in db. And change the behavior accordingly in the web app. We've a 'Manage claim' page which renders a bunch of diff views for Claim and its child entities. Now, for a readonly view we can either use the same views or have a separate set of views. What do you suggest? At controller level, we can identify archived claim and select which view to render. At model level, though it'd be great to be able to use the same model used for Manage Claim - but it might not get us the "text" of some lookup fields. For example, Claim.BrandId is rendered as a dropdown in Manage claim (requires only BrandId) but for readonly view we need 'BrandText'. Any existing ref or architecture level example would be great. Here's my prev SO post but its more about db level changes: Design a process to archive data (SQL Server 2005) Thank you.

    Read the article

  • Unable to insert DateTime format into database

    - by melvg
    I'm unable to insert the DateTime into my database. Am i writing the statement wrongly? Apparently without the DateTime, I am able to insert into the database string dateAndTime = date + " " + time; CultureInfo provider = CultureInfo.InvariantCulture; DateTime theDateTime = DateTime.ParseExact(dateAndTime, "d MMMM yyyy hh:mm tt", provider); //Create a connection, replace the data source name with the name of the SQL Anywhere Demo Database that you installed SAConnection myConnection = new SAConnection("UserID=dba;Password=sql;DatabaseName=emaDB;ServerName=emaDB"); //open the connection ; myConnection.Open(); //Create a command object. SACommand insertAccount = myConnection.CreateCommand(); //Specify a query. insertAccount.CommandText = ("INSERT INTO [meetingMinutes] (title,location,perioddate,periodtime,attenders,agenda,accountID,facilitator,datetime) VALUES ('"+title+"','" + location + "', '" + date + "','" + time + "', '" + attender + "','" + agenda + "', '" + accountID + "','" + facilitator + "','" +theDateTime+ "')"); try { insertAccount.ExecuteNonQuery(); if (title == "" || agenda == "") { btnSubmit.Attributes.Add("onclick", "displayIfSuccessfulInsert();"); //ScriptManager.RegisterStartupScript(this, GetType(), "error", "alert('Please ensure to have a title or agenda!');", true); } else { btnSubmit.Attributes.Add("onclick", "displayIfSuccessfulInsert();"); Response.Redirect("HomePage.aspx"); //ScriptManager.RegisterStartupScript(this, this.GetType(), "Redit", "alert('Minutes Created!'); window.location='" + Request.ApplicationPath + "/HomePage.aspx';", true); } } catch (Exception exception) { Console.WriteLine(exception); } finally { myConnection.Close(); } It does not insert the SQL into my database.

    Read the article

  • Enterprise Platform in Python, Design Advice

    - by Jason Miesionczek
    I am starting the design of a somewhat large enterprise platform in Python, and was wondering if you guys can give me some advice as to how to organize the various components and which packages would help achieve the goals of scalability, maintainability, and reliability. The system is basically a service that collects data from various outside sources, with each outside source having its own separate application. These applications would poll a central database and get any requests that have been submitted to perform on the external source. There will be a main website and REST/SOAP API that should also have access to the central data service. My initial thought was to use Django for the web site, web service and data access layer (using its built-in ORM), and then the outside source applications can use the web service(s) to get the information they need to process the request and save the results. Using this method would allow me to have multiple instances of the service applications running on the same or different machines to balance out the load. Are there more elegant means of accomplishing this? i've heard of messaging systems such as MQ, would something like that be beneficial in this scenario? My other thought was to use a completely separate data service not based on Django, and use some kind of remoting or remote objects (in they exist in Python) to interact with the data model. The downside here would be with the website which would become much slower if it had to push all of its data requests through a second layer. I would love to hear what other developers have come up with to achieve these goals in the most flexible way possible.

    Read the article

  • Complicated .NET factory design

    - by Tom W
    Hello SO; I'm planning to ask a fairly elaborate question that is also something of a musing here, so bear with me... I'm trying to design a factory implementation for a simulation application. The simulation will consist of different sorts of entities i.e. it is not a homogenous simulation in any respect. As a result, there will be numerous very different concrete implementations and only the very general properties will be abstracted at the top level. What I'd like to be able to do is create new simulation entities by calling a method on the model with a series of named arguments representing the parameters of the entity, and have the model infer what type of object is being described by the inbound parameters (from the names of the parameters and potentially the sequence they occur in) and call a factory method on the appropriate derived class. For example, if I pass the model a pair of parameters (Param1=5000, Param2="Bacon") I would like it to infer that the names Param1 and Param2 'belong' to the class "Blob1" and call a shared function "getBlob1" with named parameters Param1:=5000, Param2:="Bacon" whereas if I pass the model (Param1=5000, Param3=50) it would call a similar factory method for Blob2; because Param1 and Param3 in that order 'belong' to Blob2. I foresee several issues to resolve: Whether or not I can reflect on the available types with string parameter names and how to do this if it's possible Whether or not there's a neat way of doing the appropriate constructor inference from the combinatoric properties of the argument list or whether I'm going to have to bodge something to do it 'by hand'. If possible I'd like the model class to be able to accept parameters as parameters rather than as some collection of keys and values, which would require the model to expose a large number of parametrised methods at runtime without me having to code them explicitly - presumably one for every factory method available in the relevant namespace. What I'm really asking is how you'd go about implementing such a system, rather than whether or not it's fundamentally possible. I don't have the foresight or experience with .NET reflection to be able to figure out a way by myself. Hopefully this will prove an informative discussion.

    Read the article

  • OO Design: use Properties or Overloaded methods?

    - by Robert Frank
    Question about OO design. Suppose I have a base object vehicle. And two descendants: truck and automobile. Further, suppose the base object has a base method: FixFlatTire(); abstract; When the truck and automobile override the base object's, they require different information from the caller. Am I better off overloading FixFlatTire like this in the two descendant objects: Procedure Truck.FixFlatTire( OfficePhoneNumber: String; NumberOfAxles: Integer): Override; Overload; Procedure Automobile.FixFlatTire( WifesPhoneNumber: String; AAAMembershipID: String): Override; Overload; Or introducing new properties in each of the descendants and then setting them before calling FixFlatTire, like this: Truck.OfficePhoneNumber := '555-555-1212'; Truck.NumberOfAxles := 18; Truck.FixFlatTire(); Automobile.WifesPhoneNumber := '555-555-2323'; Automobile.AAAMembershipID := 'ABC'; Automobile.FixFlatTire();

    Read the article

  • Winforms App Not Displaying Graphical Elements in Design Mode

    - by Sev
    I wrote a bunch of code in the .cs file in c# for a winforms application. The application runs fine, and everything is in it's place. Something like this: using.. namespace Temp { public class Temp : Form { Button b1; TextBox t1; Temp() { b1.Text = "Some Text"; b1.Size = new Size(50,20); ... } void function1() { // stuff } static void Main() { Application.Run(new Temp()); } } } How can I modify my code (or fix it somehow) so that the design view displays the elements in their correct positions and view so that I can visually edit them instead of having to trial/error everything. Edit for Clarification My application runs fine. The problem is, that I didn't use designer to create the application and so in the designer view, the app is empty. But not empty when I run it, since everything is positioned programmatically in the .cs file. My question is, how can I fix this, so that the designer shows the objects correctly. There is no quick fix other than to redesign everything?

    Read the article

  • iPhone and iPad : Doing a "select * from something" query in a SQLite database

    - by Abramodj
    Hi folks, i'm trying to use the SQLite data base in my iPad app, and here's my function to make a query: - (void)executeQuery:(char*)query { NSString *file = [self getWritableDBPath]; NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL success = [fileManager fileExistsAtPath:file]; // If its not a local copy set it to the bundle copy if(!success) { //file = [[NSBundle mainBundle] pathForResource:DATABASE_TITLE ofType:@"db"]; [self createEditableCopyOfDatabaseIfNeeded]; } dataArray = NULL; dataArray = [NSMutableArray array]; sqlite3 *database = NULL; if (sqlite3_open([file UTF8String], &database) == SQLITE_OK) { sqlite3_exec(database, query, loadTimesCallback, dataArray, NULL); } sqlite3_close(database); [self logResults]; } if I call [self executeQuery:"select name from table1"]; everything is working fine. But if i call [self executeQuery:"select * from cars"]; the app crashes telling me that the NSMutableArray dataArray is not the right kind of variable where to set the query results. So, how can i do a "select * form table1" query, and store the results? Thanks! EDIT: Here's my loadTimesCallback method: static int loadTimesCallback(void *context, int count, char **values, char **columns) { NSMutableArray *times = (NSMutableArray *)context; for (int i=0; i < count; i++) { const char *nameCString = values[i]; [times addObject:[NSString stringWithUTF8String:nameCString]]; } return SQLITE_OK; }

    Read the article

  • VB.NET Update Access Database with DataTable

    - by sinDizzy
    I've been perusing some hep forums and some help books but cant seem to get my head wrapped around this. My task is to read data from two text files and then load that data into an existing MS Access 2007 database. So here is what i'm trying to do: Read data from first text file and for every line of data add data to a DataTable using CarID as my unique field. Read data from second text file and look for existing CarID in DataTable if exists update that row. If it doesnt exist add a new row. once im done push the contents of the DataTable to the database. What i have so far: Dim sSQL As String = "SELECT * FROM tblCars" Dim da As New OleDb.OleDbDataAdapter(sSQL, conn) Dim ds As New DataSet da.Fill(ds, "CarData") Dim cb As New OleDb.OleDbCommandBuilder(da) 'loop read a line of text and parse it out. gets dd, dc, and carId 'create a new empty row Dim dsNewRow As DataRow = ds.Tables("CarData").NewRow() 'update the new row with fresh data dsNewRow.Item("DriveDate") = dd dsNewRow.Item("DCode") = dc dsNewRow.Item("CarNum") = carID 'about 15 more fields 'add the filled row to the DataSet table ds.Tables("CarData").Rows.Add(dsNewRow) 'end loop 'update the database with the new rows da.Update(ds, "CarData") Questions: In constructing my table i use "SELECT * FROM tblCars" but what if that table has millions of records already. Is that not a waste of resources? Should i be trying something different if i want to update with new records? Once Im done with the first text file i then go to my next text file. Whats the best approach here: To First look for an existing record based on CarNum or to create a second table and then merge the two at the end? Finally when the DataTable is done being populated and im pushing it to the database i want to make sure that if records already exist with three primary fields (DriveDate, DCode, and CarNum) that they get updated with new fields and if it doesn't exist then those records get appended. Is that possible with my process? tia AGP

    Read the article

  • Visual C# Winforms App Not Displaying Graphical Elements in Design Mode

    - by Sev
    I wrote a bunch of code in the .cs file in c# for a winforms application. The application runs fine, and everything is in it's place. Something like this: using.. namespace Temp { public class Temp : Form { Button b1; TextBox t1; Temp() { b1.Text = "Some Text"; b1.Size = new Size(50,20); ... } void function1() { // stuff } static void Main() { Application.Run(new Temp()); } } } How can I modify my code (or fix it somehow) so that the design view displays the elements in their correct positions and view so that I can visually edit them instead of having to trial/error everything. Edit for Clarification My application runs fine. The problem is, that I didn't use designer to create the application and so in the designer view, the app is empty. But not empty when I run it, since everything is positioned programmatically in the .cs file. My question is, how can I fix this, so that the designer shows the objects correctly. There is no quick fix other than to redesign everything?

    Read the article

  • Regularly update database without browser/user

    - by Chris M
    I currently have a MySQL database which I was hoping to use to store regularly updated data from a temperature sensor connected to the internet. I currently have a page that, when opened, will grab the current temperature and the current timestamp and add it as an entry to the database, but I was looking for a way to do that without me refreshing the page every 5 seconds. Detail: The data comes from an Arduino Ethernet, posted to an IP address. Currently, I'm using cURL to grab the data from the IP, add a timestamp and save it to the DB. Obviously only updates when the page is refreshed (it uses PHP). Here is a live feed of the data - http://wetdreams.org.uk/ChrisProject/UI/live_graph_two.html TL;DR - Basically I need a middle man to grab the data from the IP and post it to a MySQL Edit: Thanks for all the advice. There might be a little bit of confusion, I'm looking for a solution that (ideally) doesn't require a computer to be on at all (other than the Server containing Database). Since I'm looking to store data over long periods of time (weeks), I'd like to set it up and leave a script running on the server (or Arduino) that gets the temp and posts it to the Database. In my head I would like to have a page on the server that automatically (without any browser open, or any other prompting other than a timer) calls a PHP script. Hope that clears things up!

    Read the article

  • Get Multiple Values From Database ASP.NET/C#

    - by user1043177
    I am trying to get/return multiple values from an SQL-Server database using and display them on an ASP.NET page. I am using a stored procedure to perform the SELECT command on the Database side. I am able to return the first value that matches the variable @PERSON but only one row is returned each time. Any help would be much appreciated. Database handler class public MainSQL() { _productConn = new SqlConnection(); _productConnectionString += "data source=mssql.database.co.uk;InitialCatalog=test_data;User ID=username;Password=password"; _productConn.ConnectionString = _productConnectionString; } public string GetItemName(int PersonID) { string returnvalue = string.Empty; SqlCommand myCommand = new SqlCommand("GetItem", _productConn); myCommand.CommandType = CommandType.StoredProcedure; myCommand.Parameters.Add(new SqlParameter("@PERSON", SqlDbType.Int)); myCommand.Parameters[0].Value = PersonID; _productConn.Open(); returnvalue = (string)myCommand.ExecuteScalar(); _productConn.Close(); return (string)returnvalue; } Stored Procedure USE [test_data] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [ppir].[GetItem] ( @PERSON int ) AS /*SET NOCOUNT ON;*/ SELECT Description FROM [Items] WHERE PersonID = @PERSON RETURN return.aspx namespace test { public partial class Final_Page : System.Web.UI.Page { MainSQL GetInfo; protected void Page_Load(object sender, EventArgs e) { int PersonId = (int)Session["PersonID"]; GetInfo = new MainSQL(); string itemname = GetInfo.GetItemName(PersonId); ReturnItemName.Text = itemname; } // End Page_Load } // End Class } // End Namespace

    Read the article

  • Grid related UI design question

    - by younevertell
    Grid related UI design question I want some 16-grid (4 rows and 4 columns) user interface, and fill the grid with some round shapes. I also want to use the MouseOver, mouse left button down, and Mouse Left Button Up events to set the state of grids as selected or not selected. My questions: 1. How fill the grid with some round shapes? by SetColumn and SetRow? 2. How to make the grids respond to the mouse please? Thanks <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> <ColumnDefinition /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions>

    Read the article

  • Is Storing Cookies in a Database Safe?

    - by viatropos
    If I use mechanize, I can, for instance, create a new google analytics profile for a website. I do this by programmatically filling out the login form and storing the cookies in the database. Then, for at least until the cookie expires, I can access my analytics admin panel without having to enter my username and password again. Assuming you can't create a new analytics profile any other way (with OpenAuth or any of that, I don't think it works for actually creating a new Google Analytics profile, the Analytics API is for viewing the data, but I need to create an new analytics profile), is storing the cookie in the database a bad thing? If I do store the cookie in the database, it makes it super easy to programatically login to Google Analytics without the user ever having to go to the browser (maybe the app has functionality that says "user, you can schedule a hook that creates a new anaytics profile for each new domain you create, just enter your credentials once and we'll keep you logged in and safe"). Otherwise I have to keep transferring around emails and passwords which seems worse. So is storing cookies in the database safe?

    Read the article

  • How to update csv column names with database table header

    - by user1523311
    I am facing this problem some past days and now frustrate because I have to do it. I need to update my CSV file columns name with database table header. My database table fields are different from CSV file. Now the problem is that first I want to update column name of CSV file with database table headers and then import its data with field mapping into database. Please help me I don't know how I can solve this. This is my php code: $file = $_POST['fileName']; $filename = "../files/" . $file; $list = $_POST['str']; $array_imp = implode(',', $list); $array_exp = explode(',', $array_imp); $fp = fopen("../files/" . $file, "w"); $num = count($fp); for ($c = 0; $c < $num; $c++) { if ($fp[c] !== '') { fputcsv($fp, $array_exp); } } fclose($fp);

    Read the article

  • Applying iterative algorithm to a set of rows from database

    - by Corvin
    Hello, this question may seem too basic to some, but please bear with be, it's been a while since I dealt with decent database programming. I have an algorithm that I need to program in PHP/MySQL to work on a website. It performs some computations iteratively on an array of objects (it ranks the objects based on their properties). In each iteration the algorithm runs through all collection a couple of times, accessing various data from different places of the whole collection. The algorithm needs several hundred iterations to complete. The array comes from a database. The straightforward solution that I see is to take the results of a database query and create an object for each row of the query, put the objects to an array and pass the array to my algorithm. However, I'm concerned with efficacy of such solution when I have to work with an array of several thousand of items because what I do is essentially mirror the results of a query to memory. On the other hand, making database query a couple of times on each iteration of the algorithm also seems wrong. So, my question is - what is the correct architectural solution for a problem like this? Is it OK to mirror the query results to memory? If not, which is the best way to work with query results in such an algorithm? Thanks!

    Read the article

  • Prevent cached objects to end up in the database with Entity Framework

    - by Dirk Boer
    We have an ASP.NET project with Entity Framework and SQL Azure. A big part of our data only needs to be updated a few times a day, other data is very volatile. The data that barely changes we cache in memory at startup, detach from the context and than use it mainly for reading, drastically lowering the amount of database requests we have to do. The volatile data is requested everytime by a DbContext per Http request. When we do an update to the cached data, we send a message to all instances to catch a fresh version of all the data from the SQL server. So far, so good. Until we introduced a bug that linked one of these 'cached' objects to the 'volatile' data, and did a SaveChanges. Well, that was quite a mess. The whole data tree was added again and again by every update, corrupting the whole database with a whole lot of duplicated data. As a complete hack I added a completely arbitrary column with a UniqueConstraint and some gibberish data on one of the root tables; hopefully failing the SaveChanges() next time we introduce such a bug because it will violate the Unique Constraint. But it is of course hacky, and I'm still pretty scared ;P Are there any better ways to prevent whole tree's of cached objects ending up in the database? More information Project is ASP.NET MVC I cache this data, because it is mainly read only, and this saves a tons of extra database calls per http request

    Read the article

  • Need a solution to store images (1 billion, 1000,000,000) which users will upload to a website via php or javascript upload [on hold]

    - by wish_you_all_peace
    I need a solution to store images (1 billion) which users will upload to a website via PHP or Javascript upload (website will have 1 billion page views a month using Linux Debian distros) assuming 20 photos per user maximum (10 thumbnails of size 90px by 90px and 10 large, script resized images of having maximum width 500px or maximum height 500px depending on shape of image, meaning square, rectangle, horizontal, vertical etc). Assume this to be a LEMP-stack (Linux Nginx MySQL PHP) social-media or social-matchmaking type application whose content will be text and images. Since everyone knows storing tons of images (website users uploaded images in this case) are bad inside a single directory or NFS etc, please explain all the details about the architecture and configuration of the entire setup of storage solution, to store 1 billion images on any method you recommend (no third-party cloud storage like S3 etc. It has to be within the private data center using our own hardware and resources.). The solution has to include both the storage solution and organizing the images uploaded by users. How will we organize the users images if a single user will not have more than 20 images (10 thumbs and 10 large of having either width or height 500px)? Please consider that this has to be organized in a structural way so we can fetch a single user's images via PHP/Javascript or API programmatically through some type of user's unique identifier(s).

    Read the article

  • SQL Server 2008 uses half the CPU’s

    - by ACALVETT
    I recently got my hands on a couple of 4 socket servers with Intel E7-4870's (10 cores per cpu) and with hyper threading enabled that gave me 80 logical CPU's. The server has Windows 2008 R2 SP1 along with SQL 2008 (Currently we can not deploy SQL 2008 R2 for the application being hosted). When SQL Server started I noticed only 2 NUMA nodes were configured and 40 logical cores where there should have been 4 NUMA nodes and 80 logical cores (see below). The problem is caused by that fact that...(read more)

    Read the article

< Previous Page | 286 287 288 289 290 291 292 293 294 295 296 297  | Next Page >