On 25 Mar 2017, at 7:14pm, Max Terentiev <supp...@bspdev.com> wrote:
> Sqlite have many settings combinations affecting concurrency please help me > to chose right settings for my task 1. Leave SQLITE_THREADSAFE to the default setting. 2. Leave shared cache and uncommitted reads to the default settings. Use WAL mode. This is a one-time setting which is stored in the database. Once you’ve set it every connection which opens the database automatically knows that it’s in WAL mode. Set a timeout of at least thirty seconds. You have to set this with every connection to the database (simplest to do it immediately after the sqlite3_open() command). 3. Leave locking mode to the default setting. 4. Use BEGIN without adding anything, which defaults to BEGIN DEFERRED. I’m sure you’ve noticed a pattern here. The default settings are pretty good for the way you want to use SQLite. Try the above. If you get a problem post again and we’ll try to figure out what to change. > - Bulk INSERT or DELETE records, 10000 records per transaction (several > millions records total). 15% of requests. Depending on how complicated your schema is, and the performance of your storage system, this may be a problem, an exception to the above. If inserting 10000 records in one transaction locks the database for too long, you might want to do them in batches of 1000, sleeping for a few milliseconds between blocks. But it’s likely that you will have no problem with far longer blocks. > Thanks for help and excuse me for bad English. Always fun when people post this. The people who think to post it write English better than I do. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
