On 27 Sep 2019, at 11:59pm, Roman Fleysher <roman.fleys...@einstein.yu.edu> wrote:
> From experience, it seems that because SQLite still requests file locks, the > performance increase is not that big. I wonder if there is a way to disable > SQLite's internal file locking mechanism. I know this seems strange to ask. > But FLoM should be able to do it faster over many compute nodes. What busy_timeout did you set ? Do you process multiple operations inside a transaction, or do you let SQLite create its own transactions automatically ? SQLite always locks the entire database. It does not implement table or row locking. SQLite has two (main) journalling modes. The journalling made influences which operations lock out other operations. The biggest change in lockouts occurs whether you do or do not have writes from multiple connections at once. You might want to try executing this command just once: PRAGMA journal_mode = WAL This makes a change to the database so that all connections which open it know it's in WAL mode. You don't have to change your software. It might speed things up. (You can do PRAGMA journal_mode = DELETE to set it back.) There are other other things you can do to disable various parts of the locking system, but you should try the above first. You might want to play around with <https://sqlite.org/pragma.html#pragma_synchronous> Refs: <https://sqlite.org/pragma.html#pragma_journal_mode> <https://sqlite.org/wal.html> _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users