Search Results

Search found 10028 results on 402 pages for 'berkeley db'.

Page 172/402 | < Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >

• Avoid slowdowns while using off-site database

  - by Anders Holmström

  The basic layout of my problem is this: Website (ASP.NET/C#) hosted at a dedicated hosting company (location 1) Company database (SQL Server) with records of relevant data (location 2). Location 1 & 2 connected through VPN. Customer visiting the website and wanting to pull data from the company database. No possibility of changing the server locations or layout (i.e. moving the website to an in-office server isn't possible). What I want to do is figure out the best way to handle the data acces in this case, minimizing the need for time-expensive database calls over the VPN. The first idea I'm getting is this: When a user enters the section of the website needing the DB data, you pull all the needed tables from the database into a in-memory dataset. All subsequent views/updates to the data is done on this dataset. When the user leaves (logout, session timeout, browser closed etc) the dataset gets sent to the SQL server. I'm not sure if this is a realistic solution, and it obviously has some problems. If two web visitors are performing updates on the same data, the one finishing up last will have their changes overwriting the first ones. There's also no way of knowing you have the latest data (i.e. if a customer pulls som info on their projects and we update this info while they are viewing them, they won't see these changes PLUS the above overwriting issue will arise). The other solution would be to somehow aggregate database calls and make sure they only happen when you need them, e.g. during data updates but not during data views. But then again the longer a pause between these refreshing DB calls, the bigger a chance that the data view is out of date as per the problem described above. Any input on the above or some fresh ideas would be most welcome.

  Read the article

• Prroblem with ObjectDelete() in Entity Framework 4

  - by Tom

  I got two entities: public class User : Entity { public virtual string Username { get; set; } public virtual string Email { get; set; } public virtual string PasswordHash { get; set; } public virtual List<Photo> Photos { get; set; } } and public class Photo : Entity { public virtual string FileName { get; set; } public virtual string Thumbnail { get; set; } public virtual string Description { get; set; } public virtual int UserId { get; set; } public virtual User User { get; set; } } When I try to delete the photo it works fine for the DB (record gets romoved from the table) but it doesnt for the Photos collection in the User entity (I can still see that photo in user.Photos). This is my code. What I'm doing wrong here? Changing entity properties works fine. When I change photo FileName for example it gets updated in DB and in user.Photos. var photo = SelectById(id); Context.DeleteObject(photo); Context.SaveChanges(); var user = GetUser(userName); // the photo I have just deleted is still in user.Photos also tried this but getting same results: var photo = user.Photos.First(); Context.DeleteObject(photo); Context.SaveChanges();

  Read the article

• Any suggestions to improve my PDO connection class?

  - by Scarface

  Hey guys I am pretty new to pdo so I basically just put together a simple connection class using information out of the introductory book I was reading but is this connection efficient? If anyone has any informative suggestions, I would really appreciate it. class PDOConnectionFactory{ public $con = null; // swich database? public $dbType = "mysql"; // connection parameters public $host = "localhost"; public $user = "user"; public $senha = "password"; public $db = "database"; public $persistent = false; // new PDOConnectionFactory( true ) <--- persistent connection // new PDOConnectionFactory() <--- no persistent connection public function PDOConnectionFactory( $persistent=false ){ // it verifies the persistence of the connection if( $persistent != false){ $this->persistent = true; } } public function getConnection(){ try{ $this->con = new PDO($this->dbType.":host=".$this->host.";dbname=".$this->db, $this->user, $this->senha, array( PDO::ATTR_PERSISTENT => $this->persistent ) ); // carried through successfully, it returns connected return $this->con; // in case that an error occurs, it returns the error; }catch ( PDOException $ex ){ echo "We are currently experiencing technical difficulties. We have a bunch of monkies working really hard to fix the problem. Check back soon: ".$ex->getMessage(); } } // close connection public function Close(){ if( $this->con != null ) $this->con = null; } }

  Read the article

• Django tutorial says I haven't set DATABASE_ENGINE setting yet... but I have

  - by Joe

  I'm working through the Django tutorial and receiving the following error when I run the initial python manage.py syncdb: Traceback (most recent call last): File "manage.py", line 11, in <module> execute_manager(settings) File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 362 in execute_manager utility.execute() File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 303, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 195, in run_from_argv self.execute(*args, **options.__dict__) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 222, in execute output = self.handle(*args, **options) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 351, in handle return self.handle_noargs(**options) File "/Library/Python/2.6/site-packages/django/core/management/commands/syncdb.py", line 49, in handle_noargs cursor = connection.cursor() File "/Library/Python/2.6/site-packages/django/db/backends/dummy/base.py", line 15, in complain raise ImproperlyConfigured, "You haven't set the DATABASE_ENGINE setting yet." django.core.exceptions.ImproperlyConfigured: You haven't set the DATABASE_ENGINE setting yet. My settings.py looks like: DATABASES = { 'default': { 'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'. 'NAME': 'dj_tut', # Or path to database file if using sqlite3. 'USER': '', # Not used with sqlite3. 'PASSWORD': '', # Not used with sqlite3. 'HOST': '', # Set to empty string for localhost. Not used with sqlite3. 'PORT': '', # Set to empty string for default. Not used with sqlite3. } } I'm guessing this is something simple, but why isn't it seeing the ENGINE setting?

  Read the article

• Wicket application + Apache + mod_jk - AJP queues are filling up!

  - by nojyarg

  Dear community, We are having a Wicket-based Java application deployed in a production server cluster using Apache (2.2.3) with mod_jk (1.2.30) as load balancing component w/ sticky session and Jboss 5 as application container for the Java application. We are inconsistently seeing an issue in our production environment where our AJP queues between Apache and Jboss as shown in the JMX console fill up with requests to the point where the application server is no longer taking on any new requests. When looking at all involved system components (overall traffic, load db, process list db, load of all clustered application server nodes) nothing points towards a capacity issue which would explain why the calls are being stalled in the AJP queue. Instead all systems appear sufficiently idle. So far, our only remedy to this issue is to restart the appservers and the load balancer which only occasionally clears the AJP queues. We are trying to figure out why the queues are filling up to the point that no calls get returned to the end user although the system is not under a high load. Has anyone else experienced similar problems? Are there any other system metrics we should monitor that could explain the queuing behavior? Is this potentially a mod_jk issue? If so, is it advisable to swap mod_jk with mod_cluster to resolve the issue? Any advice is highly appreciated. If I can provide additional information for the sake of troubleshooting I would be more than willing to do so. /Ben

  Read the article

• Faster Insertion of Records into a Table with SQLAlchemy

  - by Kyle Brandt

  I am parsing a log and inserting it into either MySQL or SQLite using SQLAlchemy and Python. Right now I open a connection to the DB, and as I loop over each line, I insert it after it is parsed (This is just one big table right now, not very experienced with SQL). I then close the connection when the loop is done. The summarized code is: log_table = schema.Table('log_table', metadata, schema.Column('id', types.Integer, primary_key=True), schema.Column('time', types.DateTime), schema.Column('ip', types.String(length=15)) .... engine = create_engine(...) metadata.bind = engine connection = engine.connect() .... for line in file_to_parse: m = line_regex.match(line) if m: fields = m.groupdict() pythonified = pythoninfy_log(fields) #Turn them into ints, datatimes, etc if use_sql: ins = log_table.insert(values=pythonified) connection.execute(ins) parsed += 1 My two questions are: Is there a way to speed up the inserts within this basic framework? Maybe have a Queue of inserts and some insertion threads, some sort of bulk inserts, etc? When I used MySQL, for about ~1.2 million records the insert time was 15 minutes. With SQLite, the insert time was a little over an hour. Does that time difference between the db engines seem about right, or does it mean I am doing something very wrong?

  Read the article

• WPF ObservableCollection in xaml

  - by Cloverness

  Hi, I have created an ObservableCollection in the code behind of a user control. It is created when the window loads: private void UserControl_Loaded(object sender, RoutedEventArgs e) { Entities db = new Entities(); ObservableCollection<Image> _imageCollection = new ObservableCollection<Image>(); IEnumerable<library> libraryQuery = from c in db.ElectricalLibraries select c; foreach (ElectricalLibrary c in libraryQuery) { Image finalImage = new Image(); finalImage.Width = 80; BitmapImage logo = new BitmapImage(); logo.BeginInit(); logo.UriSource = new Uri(c.url); logo.EndInit(); finalImage.Source = logo; _imageCollection.Add(finalImage); } } I need to get the ObservableCollection of images which are created based on the url saved in a database. But I need a ListView or other ItemsControl to bind to it in XAML file like this: But I can't figure it out how to pass the ObservableCollection to the ItemsSource of that control. I tried to create a class and then create an instance of a class in xaml file but it did not work. Should I create a static resource somehow Any help will be greatly appreciated.

  Read the article

• get and set for class in model - MVC 2 asp.net

  - by bergin

  Hi there, I want to improve the program so it has a proper constructor but also works with the models environment of MVC. I currently have: public void recordDocument(int order_id, string filename, string physical_path, string slug, int bytes) { ArchiveDocument doc = new ArchiveDocument(); doc.order_id = order_id; doc.filename = filename; doc.physical_path = physical_path; doc.slug = slug; doc.bytes = bytes; db.ArchiveDocuments.InsertOnSubmit(doc); } This obviously should be a constructor and should change to the leaner: public void recordDocument(ArchiveDocument doc) { db.ArchiveDocuments.InsertOnSubmit(doc); } with a get & set somewhere else - not sure of the syntax - do I create a partial class? so: creating in the somewhere repository - ArchiveDocument doc = new ArchiveDocument(order_id, idTaggedFilename, physical_path, slug, bytes); and then: namespace ordering.Models { public partial class ArchiveDocument { int order_id, string filename, string physical_path, string slug, int bytes; public archiveDocument(int order_id, string filename, string physical_path, string slug, int bytes){ this.order_id = order_id; etc } } How should I alter the code?

  Read the article

• NHibernate will not insert a record

  - by Brian Beckham

  I have an application that is now 4+ years old that is exhibiting some odd behavior on our latest deployment. The application uses nHibernate for all inserts / updates / selects, etc. We are currently using .NET 2.0, and nHibernate 1.2 (I know, we need to upgrade) This deployment is on Windows 2008 Server x64, IIS 7.5 - what I have seen so far is that the application runs, but is unable to insert or update records in the DB - reads seem fine so far, but writes are a problem. SOME writes actually work, inserts into some small tables, but most never even make it to the DB. Using SQL Profiler, the insert / updates never make it to the server, and turning log4net up to DEBUG, and show_sql true - the select statements appear, but the insert / update statements never make it into the log at all, and never show up at the server. What's even more odd is that the application seems to be oblivious to this - the commandandclose runs without exception (open session in view with an httpmodule), the domain objects come back with uuid's generated, etc. but never get persisted. Certainly an upgrade is due, but I would hate to try it during a deployment, and without time to accurately test the app. Any ideas?

  Read the article

• Updating database row from model

  - by Jamie Dixon

  Hey everyone, I'm haing a few problems updating a row in my database using Linq2Sql. Inside of my model I have two methods for updating and saving from my controller, which in turn receives an updated model from my view. My model methods like like: public void Update(Activity activity) { _db.Activities.InsertOnSubmit(activity); } public void Save() { _db.SubmitChanges(); } and the code in my Controller likes like: [HttpPost] public ActionResult Edit(Activity activity) { if (ModelState.IsValid) { UpdateModel<Activity>(activity); _activitiesModel.Update(activity); _activitiesModel.Save(); } return View(activity); } The problem I'm having is that this code inserts a new entry into the database, even though the model item i'm inserting-on-submit contains a primary key field. I've also tried re-attaching the model object back to the data source but this throws an error because the item already exists. Any pointers in the right direction will be greatly appreciated. UPDATE: I'm using dependancy injection to instantiate my datacontext object as follows: IMyDataContext _db; public ActivitiesModel(IMyDataContext db) { _db = db; }

  Read the article

• Solr - DeltaImport doenst run the parentDeltaQuery

  - by rails

  I have 1:n relation between my main entity(PackageVersion) and its tag in my DB. I add a new tag with this date to the db at the timestamp and I run delta import command. the select retrieves the line but i dont see any other sql. Here are my data-config.xml configurations: <entity name="PackageVersion" pk="PackageVersionId" query= "select ... from [dbo].[Package] Package inner join [dbo].[PackageVersion] PackageVersion on Package.Id = PackageVersion.PackageId" deltaQuery = "select PackageVersion.Id PackageVersionId from [dbo].[Package] Package inner join [dbo].[PackageVersion] PackageVersion on Package.Id = PackageVersion.PackageId where Package.LastModificationTime > '${dataimporter.last_index_time}' OR PackageVersion.Timestamp > '${dataimporter.last_index_time}'" deltaImportQuery="select ... from [dbo].[Package] Package inner join [dbo].[PackageVersion] PackageVersion on Package.Id = PackageVersion.PackageId Where PackageVersionId=='${dih.delta.id}'" > <entity name="PackageTag" pk="ResourceId" processor="CachedSqlEntityProcessor" cacheKey="ResourceId" cacheLookup="PackageVersion.PackageId" query= "SELECT ResourceId,[Text] PackageTag from [dbo].[Tag] Tag" deltaQuery="SELECT ResourceId,[Text] PackageTag from [dbo].[Tag] Tag Where Tag.TimeStamp > '${dataimporter.last_index_time}'" parentDeltaQuery="select PackageVersion.PackageVersionId from [dbo].[Package] where Package.Id=${PackageTag.ResourceId}"> </entity> </entity>

  Read the article

• Cleaning up PHP Code

  - by Michael

  Hi, I've noticed I am a very sloppy coder and do things out of the ordinary. Can you take a look at my code and give me some tips on how to code more efficiently? What can I do to improve? session_start(); /check if the token is correct/ if ($_SESSION['token'] == $_GET['custom1']){ /*connect to db*/ mysql_connect('localhost','x','x') or die(mysql_error()); mysql_select_db('x'); /*get data*/ $orderid = mysql_real_escape_string($_GET['order_id']); $amount = mysql_real_escape_string($_GET['amount']); $product = mysql_real_escape_string($_GET['product1Name']); $cc = mysql_real_escape_string($_GET['Credit_Card_Number']); $length = strlen($cc); $last = 4; $start = $length - $last; $last4 = substr($cc, $start, $last); $ipaddress = mysql_real_escape_string($_GET['ipAddress']); $accountid = $_SESSION['user_id']; $credits = mysql_real_escape_string($_GET['custom3']); /*insert history into db*/ mysql_query("INSERT into billinghistory (orderid, price, description, credits, last4, orderip, accountid) VALUES ('$orderid', '$amount', '$product', '$credits', '$last4', '$ipaddress', '$accountid')"); /*add the credits to the users account*/ mysql_query("UPDATE accounts SET credits = credits + $credits WHERE user_id = '$accountid'"); /*redirect is successful*/ header("location: index.php?x=1"); }else{ /*something messed up*/ header("location: error.php"); }

  Read the article

• Cannot open database requested by the login. The login failed. Login failed for user

  - by Cipher

  Hi, I have copied a DB from one my computers and using it here. On trying to open the page which requires the fetching content from DB, on con.open I am getting this exception: Unable to open the physical file "E:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\cakephp.mdf". Operating system error 32: "32(The process cannot access the file because it is being used by another process.)". Unable to open the physical file "E:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\cakephp_log.LDF". Operating system error 32: "32(The process cannot access the file because it is being used by another process.)". Cannot open database "cakephp" requested by the login. The login failed. Login failed for user 'Sarin-PC\Sarin'. I have attached the database from Management Studio Express 2008 and I have also checcked the connection string. Here it is: <connectionStrings> <add name="cn" connectionString="server=.\sqlexpress;database=cakephp;integrated security=true;uid=sarin;pwd=******"/> </connectionStrings> In Visual Studio, when I test the connection, it says "Test connection succeeded". However, there is one strange thing going on. When I login to the Management Studio, there is no + sign with the newly attached database, as shown. If the full WebConfig is reqiured to be seen, I have pasted it here: http://pastebin.com/sVAuN0Ug

  Read the article

• MD5CryptoServiceProvider ComputeHash Issues between VS 2003 and VS 2008

  - by owensoroke

  I have a database application that generates a MD5 hash and compares the hash value to a value in our DB (SQL 2K). The original application was written in Visual Studio 2003 and a deployed version has been working for years. Recently, some new machines on the .NET framework 3.5 have been having unrelated issues with our runtime. This has forced us to port our code path from Visual Studio 2003 to Visual Studio 2008. Since that time the hash produced by the code is different than the values in the database. The original call to the function posted in code is: RemoveInvalidPasswordCharactersFromHashedPassword(Text_Scrub(GenerateMD5Hash(strPSW))) I am looking for expert guidance as to whether or not the MD5 methods have changed since VS 2K3 (causing this point of failure), or where other possible problems may be originating from. I realize this may not be the best method to hash, but utimately any changes to the MD5 code would force us to change some 300 values in our DB table and would cost us a lot of time. In addition, I am trying to avoid having to redeploy all of the functioning versions of this application. I am more than happy to post other code including the RemoveInvalidPasswordCharactersFromHashedPassword function, or our Text_Scrub if it is necessary to recieve appropriate feedback. Thank you in advance for your input. Public Function GenerateMD5Hash(ByVal strInput As String) As String Dim md5Provider As MD5 ' generate bytes for the input string Dim inputData() As Byte = ASCIIEncoding.ASCII.GetBytes(strInput) ' compute MD5 hash md5Provider = New MD5CryptoServiceProvider Dim hashResult() As Byte = md5Provider.ComputeHash(inputData) Return ASCIIEncoding.ASCII.GetString(hashResult) End Function

  Read the article

• Inefficient 'ANY' LINQ clause

  - by Focus

  I have a query that pulls back a user's "feed" which is essentially all of their activity. If the user is logged in the query will be filtered so that the feed not only includes all of the specified user's data, but also any of their friends. The database structure includes an Actions table that holds the user that created the action and a UserFriends table which holds any pairing of friends using a FrienderId and FriendeeId column which map to UserIds. I have set up my LINQ query and it works fine to pull back the data I want, however, I noticed that the query gets turned into X number of CASE clauses in profiler where X is the number of total Actions in the database. This will obviously be horrible when the database has a user base larger than just me and 3 test users. Here's the SQL query I'm trying to achieve: select * from [Action] a where a.UserId = 'GUID' OR a.UserId in (SELECT FriendeeId from UserFriends uf where uf.FrienderId = 'GUID') OR a.UserId in (SELECT FrienderId from UserFriends uf where uf.FriendeeId = 'GUID') This is what I currently have as my LINQ query. feed = feed.Where(o => o.User.UserKey == user.UserKey || db.Users.Any(u => u.UserFriends.Any(ufr => ufr.Friender.UserKey == user.UserKey && ufr.isApproved) || db.Users.Any(u2 => u2.UserFriends.Any(ufr => ufr.Friendee.UserKey == user.UserKey && ufr.isApproved) ))); This query creates this: http://pastebin.com/UQhT90wh That shows up X times in the profile trace, once for each Action in the table. What am I doing wrong? Is there any way to clean this up?

  Read the article

• Creating multiple instances of a generic database

  - by sagekilla

  Hi all, currently I'm trying to have a setup where a generic database is distributed to students. They would develop an application using this database (Say a shopping cart application), submit their project onto our server, and then it would be graded automatically. These databases are being run in Microsoft SQL Server 2005. We're using user instances to instantiate each database, and multiple requests could be serviced at once. But, the problem is when more than one student submitted a project to be graded, the first database to be instantiated would be the only one and would overwrite all other copies that were currently open. So if stu1 modified his database and stu2 and stu3 had their projects being graded concurrently, at the end of the grading stu1, stu2, and stu3 would have identical DB's at the end. Is there any way I can have multiple independent copies of a generic database, each of which I can load concurrently and modify without having any changes made to any one affecting the others? I did a little reading, and thought it might be possible to do something along the lines of: Student submits project Attach the database with unique db name (specified by student) Do all necessary operations Detach the database I'm unsure if this would fix our problem or be possible, so any help would be much appreciated!

  Read the article

• Creating android app Database with big amount of data

  - by Thomas

  Hi all, The database of my application need to be filled with a lot of data, so during onCreate(), it's not only some create table sql instructions, there is a lot of inserts. The solution I chose is to store all this instructions in a sql file located in res/raw and which is loaded with Resources.openRawResource(id). It works well but I face to encoding issue, I have some accentuated caharacters in the sql file which appears bad in my application. This my code to do this : public String getFileContent(Resources resources, int rawId) throws IOException { InputStream is = resources.openRawResource(rawId); int size = is.available(); // Read the entire asset into a local byte buffer. byte[] buffer = new byte[size]; is.read(buffer); is.close(); // Convert the buffer into a string. return new String(buffer); } public void onCreate(SQLiteDatabase db) { try { // get file content String sqlCode = getFileContent(mCtx.getResources(), R.raw.db_create); // execute code for (String sqlStatements : sqlCode.split(";")) { db.execSQL(sqlStatements); } Log.v("Creating database done."); } catch (IOException e) { // Should never happen! Log.e("Error reading sql file " + e.getMessage(), e); throw new RuntimeException(e); } catch (SQLException e) { Log.e("Error executing sql code " + e.getMessage(), e); throw new RuntimeException(e); } The solution I found to avoid this is to load the sql instructions from a huge static final string instead of a file, and all accentutated characters appears well. But Isn't there a more elegant way to load sql instructions than a big static final String attribute with all sql instructions ? Thanks in advance Thomas

  Read the article

• How can I debug PEAR auth?

  - by croceldon

  I have a directory on my site that I've implemented PEAR's Auth to run my authentication. It is working great. However, I've tried to make a copy of my site (it's going to be translated to a different language), and on this new site, the Auth process doesn't seem to be working correctly. I can login properly, but every time I try to go to a different page in the same directory, and use Auth to authorize, it forces me to login again. Here's my logic: $auth_options = array( 'dsn' => mysql://user:password@server/db', 'table' => 'users', 'usernamecol' => 'username', 'passwordcol' => 'password', 'db_fields' => '*' ); $auth = new Auth("DB", $auth_options, "login_function"); $auth->setFailedLoginCallback('bad_login'); $auth->start(); if (!$auth->checkAuth()) { die('cannot succeed in checkAuth') exit; } else { include("nocache.php"); } This is part of a file that's included in every php page I that I desire to require authentication. I can login properly once, but whenever I then try to go to a different page that requires authentication, it makes me login again (and I see the 'cannot succeed' die message at the bottom of the page). Again, this solution works fine on my original site, I copied all the files, and only changed the db server/password - it still doesn't work. And I'm using the same webhost for both. What am I doing wrong here? Or how can I debug this further?

  Read the article

• How can I make "month" columns in Sql?

  - by Beska

  I've got a set of data that looks something like this (VERY simplified): productId Qty dateOrdered --------- --- ----------- 1 2 10/10/2008 1 1 11/10/2008 1 2 10/10/2009 2 3 10/12/2009 1 1 10/15/2009 2 2 11/15/2009 Out of this, we're trying to create a query to get something like: productId Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec --------- ---- --- --- --- --- --- --- --- --- --- --- --- --- 1 2008 0 0 0 0 0 0 0 0 0 2 1 0 1 2009 0 0 0 0 0 0 0 0 0 3 0 0 2 2009 0 0 0 0 0 0 0 0 0 3 2 0 The way I'm doing this now, I'm doing 12 selects, one for each month, and putting those in temp tables. I then do a giant join. Everything works, but this guy is dog slow. I know this isn't much to go on, but knowing that I barely qualify as a tyro in the db world, I'm wondering if there is a better high level approach to this that I might try. (I'm guessing there is.) (I'm using MS Sql Server, so answers that are specific to that DB are fine.) (I'm just starting to look at "PIVOT" as a possible help, but I don't know anything about it yet, so if someone wants to comment about that, that might be helpful as well.)

  Read the article

• Storing large numbers of varying size objects on disk

  - by Foredecker

  I need to develop a system for storing large numbers (10's to 100's of thousands) of objects. Each object is email-like - there is a main text body, and several ancillary text fields of limited size. A body will be from a few bytes, to several KB in size. Each item will have a single unique ID (probably a GUID) that identifies it. The store will only be written to when an object is added to it. It will be read often. Deletions will be rare. The data is almost all human readable text so it will be readily compressible. A system that lets me issue the I/Os and mange the memory and caching would be ideal. I'm going to keep the indexes in memory, using it to map indexes to the single (and primary) key for the objects. Once I have the key, then I'll load it from disk, or the cache. The data management system needs to be part of my application - I do not want to depend on OS services. Or separately installed packages. Native (C++) would be best, but a manged (C#) thing would be ok. I believe that a database is an obvious choice, but this needs to be super-fast for look up and loading into memory of an object. I am not experienced with data base tech and I'm concerned that general relational systems will not handle all this variable sized data efficiently. (Note, this has nothing to do with my job - its a personal project.) In your experience, what are the viable alternatives to a traditional relational DB? Or would a DB work well for this?

  Read the article

• django multiprocess problem

  - by iKiR

  I have django application, running under lighttpd via fastcgi. FCGI running script looks like: python manage.py runfcgi socket=<path>/main.socket method=prefork \ pidfile=<path>/server.pid \ minspare=5 maxspare=10 maxchildren=10 maxrequests=500 \ I use SQLite. So I have 10 proccess, which all work with the same DB. Next I have 2 views: def view1(request) ... obj = MyModel.objects.get_or_create(id=1) obj.param1 = <some value> obj.save () def view2(request) ... obj = MyModel.objects.get_or_create(id=1) obj.param2 = <some value> obj.save () And If this views are executed in two different threads sometimes I get MyModel instance in DB with id=1 and updated either param1 or param2 (BUT not both) - it depends on which process was the first. (of course in real life id changes, but sometimes 2 processes execute these two views with same id) The question is: What should I do to get instance with updated param1 and param2? I need something for merging changes in different processes. One decision is create interprocess lock object but in this case I will get sequence executing views and they will not be able to be executed simultaneously, so I ask help

  Read the article

• UIImage Object surprisingly returning null but not NSData

  - by riyaz

  i have created a sqlite db. and i have insert a few datas in my db.. UIImage * imagee=[UIImage imageNamed:@"image.png"]; NSData *mydata=[NSData dataWithData:UIImagePNGRepresentation(imagee)]; const char *dbpath = [databasePath UTF8String]; NSString *insertSQL=[NSString stringWithFormat:@"insert into CONTACTS values(\"%@\",\"%@\")",@"Mathan",mydata]; NSLog(@"mydata %@",mydata); sqlite3_stmt *addStatement; const char *insert_stmt=[insertSQL UTF8String]; if (sqlite3_open(dbpath,&contactDB)==SQLITE_OK) { sqlite3_prepare_v2(contactDB,insert_stmt,-1,&addStatement,NULL); if (sqlite3_step(addStatement)==SQLITE_DONE) { sqlite3_bind_blob(addStatement,1, [mydata bytes], [mydata length], SQLITE_TRANSIENT); NSLog(@"Data saved"); } else{ NSLog(@"Some Error occured"); } sqlite3_close(contactDB); } else{ NSLog(@"Failure"); } have written some codes to retrive the data sqlite3_stmt *statement; if (sqlite3_open([databasePath UTF8String], &contactDB) == SQLITE_OK) { NSString *sql = [NSString stringWithFormat:@"SELECT * FROM contacts"]; if (sqlite3_prepare_v2( contactDB, [sql UTF8String], -1, &statement, nil) == SQLITE_OK) { while (sqlite3_step(statement) == SQLITE_ROW) { char *field1 = (char *) sqlite3_column_text(statement, 0); NSString *field1Str = [[NSString alloc] initWithUTF8String: field1]; NSLog(@"UserName %@",field1Str); NSData *data = [[NSData alloc] initWithBytes:sqlite3_column_blob(statement, 1) length:sqlite3_column_bytes(statement, 1)]; UIImage *newImage = [[UIImage alloc]initWithData:data]; NSLog(@"Image OBJ %@",newImage); NSLog(@"Image Data %@",data); } sqlite3_close(contactDB); } } sqlite3_finalize(statement); the problem is in log, inserted NSData object and retrieved NSData Objects are different (printing in log gives different stream) moreover Image OBJ is printed null in log.. Have seen similar questions in stackoverflow. But nothing seems to help. Please give some suggestions to overcome this issue.

  Read the article

• DOM manipulation

  - by bluedaniel

  Hello everyone, Im trying to use the DOM in PHP to do a pretty specific job and Ive got no luck so far, the objective is to take a string of HTML from a Wordpress blog post (from the DB, this is a wordpress plugin). And then out of that HTML replace <div id="do_not_edit">old content</div>" with <div id="do_not_edit">new content</div>" in its place. Saving anything above and below that div in its structure. Then save the HTML back into the DB, should be simple really, I have read that a regex wouldnt be the right way to go here so Ive turned to the DOM instead. The problem is I just cant get it to work, cant extract the div or anything. Help me!! UPDATE The HTML coming out of the wordpress table looks like: Congratulations on finding us here on the world wide web, we are on a mission to create a website that will show off your culinary skills better than any other website does. <div id="do_not_edit">blah blah</div> We want this website to be fun and easy to use, we strive for simple elegance and incredible functionality.We aim to provide a 'complete package'. By this we want to create a website where people can meet, share ideas and help each other out. After several different (incorrect) workings all Ive got below is: $content = ($wpdb->get_var( "SELECT `post_content` FROM $wpdb->posts WHERE ID = {$article[post_id]}" )); $doc = new DOMDocument(); $doc->validateOnParse = true; $doc->loadHTMLFile($content); $element = $doc->getElementById('do_not_edit'); echo $element;

  Read the article

• codeigniter active record and mysql

  - by sea_1987

  I am running a query with Active Record in a modal of my codeigniter application, the query looks like this, public function selectAllJobs() { $this->db->select('*') ->from('job_listing') ->join('job_listing_has_employer_details', 'job_listing_has_employer_details.employer_details_id = job_listing.id', 'left'); //->join('employer_details', 'employer_details.users_id = job_listing_has_employer_details.employer_details_id'); $query = $this->db->get(); return $query->result_array(); } This returns an array that looks like this, [0]=> array(13) { ["id"]=> string(1) "1" ["job_titles_id"]=> string(1) "1" ["location"]=> string(12) "Huddersfield" ["location_postcode"]=> string(7) "HD3 4AG" ["basic_salary"]=> string(19) "£20,000 - £25,000" ["bonus"]=> string(12) "php, html, j" ["benefits"]=> string(11) "Compnay Car" ["key_skills"]=> string(1) "1" ["retrain_position"]=> string(3) "YES" ["summary"]=> string(73) "Lorem Ipsum is simply dummy text of the printing and typesetting industry" ["description"]=> string(73) "Lorem Ipsum is simply dummy text of the printing and typesetting industry" ["job_listing_id"]=> NULL ["employer_details_id"]=> NULL } } The job_listing_id and employer_details_id return as NULL however if I run the SQL in phpmyadmin I get full set of results, the query i running in phpmyadmin is, SELECT * FROM ( `job_listing` ) LEFT JOIN `job_listing_has_employer_details` ON `job_listing_has_employer_details`.`employer_details_id` LIMIT 0 , 30 Is there a reason why I am getting differing results?

  Read the article

• Having a problem inserting into database

  - by neo skosana

  I have a stored procedure: CREATE PROCEDURE busi_reg(IN instruc VARCHAR(10), IN tble VARCHAR(20), IN busName VARCHAR(50), IN busCateg VARCHAR(100), IN busType VARCHAR(50), IN phne VARCHAR(20), IN addrs VARCHAR(200), IN cty VARCHAR(50), IN prvnce VARCHAR(50), IN pstCde VARCHAR(10), IN nm VARCHAR(20), IN surname VARCHAR(20), IN eml VARCHAR(50), IN pswd VARCHAR(20), IN srce VARCHAR(50), IN refr VARCHAR(50), IN sess VARCHAR(50)) BEGIN INSERT INTO b_register SET business_name = busName, business_category = busCateg, business_type = busType, phone = phne, address = addrs, city = cty, province = prvnce, postal_code = pstCde, firstname = nm, lastname = surname, email = eml, password = pswd, source = srce, ref_no = refr; END; This is my php script: $busName = $_POST['bus_name']; $busCateg = $_POST['bus_cat']; $busType = $_POST['bus_type']; $phne = $_POST['phone']; $addrs = $_POST['address']; $cty = $_POST['city']; $prvnce = $_POST['province']; $pstCde = $_POST['postCode']; $nm = $_POST['name']; $surname = $_POST['lname']; $eml = $_POST['email']; $srce = $_POST['source']; $ref = $_POST['ref_no']; $result2 = $db->query("CALL busi_reg('$instruc', '$tble', '$busName', '$busCateg', '$busType', '$phne', '$addrs', '$cty', '$prvnce', '$pstCde', '$nm', '$surname', '$eml', '$pswd', '$srce', '$refr', '')"); if($result) { echo "Data has been saved"; } else { printf("Error: %s\n",$db->error); } Now the error that I get: Commands out of sync; you can't run this command now

  Read the article

< Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >