I have to apologize: I had the PRAGMA options confused. My application makes exclusive use of PRAGMA journal_mode=WAL.
What I meant to say was that the WAL log file is never truncated, except for it being removed when the database connection is closed successfully. On 19 September 2011 15:02, Simon Slavin <slav...@bigfraud.org> wrote: > > On 19 Sep 2011, at 2:42pm, Jaco Breitenbach wrote: > > > On 19 September 2011 13:23, Simon Slavin <slav...@bigfraud.org> wrote: > > > >> If you're actually concerned about filesize, then WAL mode is probably > not > >> the right mode to use. You may be better off with 'PRAGMA journal_mode > = > >> DELETE'. If your platform stores data on an SSD, then you may be better > off > >> with 'PRAGMA journal_mode = PERSIST'. For further details see > > > > My application is currently using the PERSIST journal mode. Actual file > > size is not important. I've mentioned the file sizes only to add more > > detail and a clearer indication of where I get the numbers from. The > > PERSIST mode is used because it seems to have the least overhead of the > > available journal modes. > > Okay. If I understand the page correctly, then if you have the mode set to > 'PERSIST' then you are not using WAL mode. This means SQLite uses the > journal file (what you called the log file) very differently and you should > ignore the link to <http://www.sqlite.org/draft/wal.html#ckpt> I posted > earlier. Also, it means that ... > > On 19 Sep 2011, at 10:13am, Jaco Breitenbach wrote: > > > When it comes to checkpointing (every 10 minutes), I assume the log file > is > > read once in its entirety, and the data file written once for every > record > > inserted. > > > If you're not using WAL mode, then I don't think the journal file will ever > be read in its entirety unless SQLite is trying to recover from a crash or > power failure. In this mode the data file is kept pretty-much up-to-date. > The journal file contains rollback and recovery information. > > Simon. > _______________________________________________ > 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
