thanks for your reply. since my situation IS one process that tries to write to the database, I'm trying to use the forums help. if the situation was multiple processes as you described I would move to mysql or MSaccess database which is quite stable for web applications. I've programmed few web projects with the sqlite database which never had this problem. and those projects are running well, that's why I think I've got a special situation.
it seems I will, have to move to another database. thanks Shahar. 2012/1/29 Jan Hudec <b...@ucw.cz> > On Sun, Jan 29, 2012 at 12:57:21 +0200, Shahar Weinstein wrote: > > I don't think that the TMP folder is the right direction but I'll check > it > > anyway with the hosting company. > > No, *NOT* *HOSTING* *COMPANY*. Your code. > > I agree it's probably not the right direction though. > > > besides that, I do know that there is only one process running that tries > > to write to the database what makes my situation a sad joke. sqlite > > supposed to be a strong database that knows how to deal such simple > > situations. > > So you are saying, that there is absolutely no other client using the code > at > the same time or even that the same client isn't using two windows? Because > otherwise any serious web server will run mutliple instances of your code > in > either multiple threads or multiple processes. > > > even of 2 processes that tries to write to the database the same time, > else > > it's probably a very weak database system that doesn't have transactions > > locks mechanism inside. > > It DOES. But very coarse-grained and is telling you the one process has it > locked, so the other process can't access it. > > Sqlite is designed to be lightweight. The cost for this is, that it does > not > have per-row or per-table locks. A write transactions always needs to lock > the whole database. Additionally by default when the database is locked, > the > operation immediately fails with the "database is locked" error you are > seeing. > > You need to do three things: > > - Run 'PRAGMA journal=wal' on the database once (see > http://www.sqlite.org/wal.html). This requires sqlite at least 3.7.0. > - Set the timeout, so the operations wait for the other process to finish > for some time instead of failing. The C-level API is sqlite3_busy_timeout > (http://www.sqlite.org/c3ref/busy_timeout.html). The .NET api will be > called similar. > - Plan eventual migration to SQL Server or MySQL or something, because > sqlite will not scale. It's designed to be fast for data processing and > small so it can be embedded in desktop or even mobile applications, but > that means it does not support multiple servers and parallel > transactions. > It can work fine in web app that gets at most few hits a minute, but for > higher load you will definitiely need a database server. > > -- > Jan 'Bulb' Hudec < > b...@ucw.cz> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
