On 5/8/12 1:51 PM, "Tilsley, Jerry M." <jmtils...@st-claire.org> wrote:
>This is probably a newbie question so please bear with me. I'm accessing >a SQLite database through TCL and periodically I get a "Database Locked" >error. This is a multi-thread process that writes to the DB, do I need >to enable WAL for this, if so, do I do this from the TCL side or the >command-line side? If only one thread is writing, then using WAL should do the trick; the other threads can read while the writer is writing. If multiple threads are writing, that's a whole different issue, and WAL (while it might still be a good idea) won't prevent the problem. You enable WAL mode using the "journal_mode" pragma; once it's set it's persistent. So you'd want to set it when creating a new database, wherever you do that; on an existing database, wherever you like. See sqlite.org/wal/html. If you've gotten multiple writers you can set a lock timeout using the database handle's "timeout" subcommand; it defaults to 0.0. You'll still need to handle lock errors, though; a timeout isn't a guarantee. Will -- Will Duquette -- william.h.duque...@jpl.nasa.gov Athena Development Lead -- Jet Propulsion Laboratory "It's amazing what you can do with the right tools." > >________________________________ > >Disclaimer**** >This email is confidential and intended solely for the use of the >individual to whom it is addressed. Any views or opinions presented are >solely those of the author and do not necessarily represent those of St. >Claire Regional Medical Center. If you are not the intended recipient, be >advised that you have received this email in error and that any use, >dissemination, forwarding, printing or copying of the email is strictly >prohibited. If you received this email in error please notify the St. >Claire Regional Helpdesk by telephone at 606-783-6565. >_______________________________________________ >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
