But the following link http://www.sqlite.org/cvstrac/wiki/wiki?p=MultiThreading says nothing that I have to synchronize at the application level to create multiple connections, until the same database connection is being shared! Ref: The four points in 'Short Answer' section.
BTW: for a DBMS it does not make sense if the application programmer has to synchronize to create multiple connection. And synhing will have considerable performance drop also. On 6/18/07, John Stanton <[EMAIL PROTECTED]> wrote:
Threadsafe only means that threads do not access global data elements or that they synchronize (serialize) access to global data. It does nothing to synchronize threads. That is up to the application programmer. Sqlite uses POSIX file locks for synchronixation but if you are in a totally threaded environment you can use thread sync functions like mutexes or the finer grained read and write lock thread primitives. If you are accessing Sqlite across a network file locks are the way to go, but do depend upon network implementations and settings. If you have multiple processes on one OS you can sync using semaphores. Using textbook style synchronization ensures that you have minimal problems and optimal performance. Sabyasachi Ruj wrote: > But I think we do not have to take care of synchronizing sqlite access. > sqlite internally does if it is compiled with THREADSAFE=1. > > On 6/18/07, John Stanton <[EMAIL PROTECTED]> wrote: > >> >> The problem is fairly straight forward. Sqlite is a single resource >> being shared by multiple thyreads so you just use fundamental >> synchronization logic as you would when sharing any resource between >> competing threads. >> >> Sabyasachi Ruj wrote: >> > Hi, >> > >> > I am using sqlite in a multithreaded environment. I have take >> > reasonable like not sharing sqlite* handles. I am creating a new >> sqlite* >> >> > for >> > every thread. >> > >> > Where can we get more info on working with SQLite in a multithreaded >> > environment? >> > >> > The application is working as a service in windows. >> > >> > sqlite3_step() is failing with the following error message: >> > >> > * SQL error or missing database >> > SQL logic error or missing database* >> > >> > I am getting this message after running the application for quite a >> long >> > time (few days). >> > And then if I execute *PRAGMA INTEGRITY_CHECK* on that table, I get the >> > same >> > error message. >> > >> > My application updates the database very 2 mins and the corruption >> happend >> > randomly >> > >> > I dont have any clue how to debug this! >> > >> > Thanks. >> > >> > On 5/11/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: >> > >> >> "Sabyasachi Ruj" < [EMAIL PROTECTED]> wrote: >> >> > Hi, >> >> > Is there any way to programmatically fix a corrupted sqlite >> database? >> >> > I am using sqlite version 3.3.8 with C APIs >> >> > >> >> >> >> Sometimes VACUUM or REINDEX will help, but usually not. >> >> You can also try to recover using: >> >> >> >> sqlite3 OLD.DB .dump | sqlite3 NEW.DB >> >> >> >> But that doesn't always work either. The best approach >> >> is to avoid corruption in the first place. >> >> -- >> >> D. Richard Hipp <[EMAIL PROTECTED]> >> >> >> >> >> >> >> >> >> ----------------------------------------------------------------------------- >> >> >> >> >> >> To unsubscribe, send email to [EMAIL PROTECTED] >> >> >> >> >> ----------------------------------------------------------------------------- >> >> >> >> >> >> >> >> >> > >> > >> >> >> >> ----------------------------------------------------------------------------- >> >> To unsubscribe, send email to [EMAIL PROTECTED] >> >> ----------------------------------------------------------------------------- >> >> >> > > ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
-- Sabyasachi
