On Tue, Feb 14, 2012 at 3:20 PM, Marc L. Allen <[email protected]>wrote:
> I think you're mixing up database size and transaction size. > > WAL starts having issues when a single transaction commits 100's of > megabytes or more of data. I believe there is no issue with very large > databases, provided the actual transactions are relatively small. > Yup. See the 9th item under disadvantages of WAL mode list at http://www.sqlite.org/wal.html > > > -----Original Message----- > > From: [email protected] [mailto:sqlite-users- > > [email protected]] On Behalf Of Aemon Cannon > > Sent: Tuesday, February 14, 2012 3:03 PM > > To: [email protected] > > Subject: [sqlite] WAL mode, references to IO errors > > > > Hello, > > > > In reading about WAL mode, I found the following passage disconcerting: > > > > "WAL works best with smaller transactions. WAL does not work well for > > very large transactions. For transactions larger than about 100 > > megabytes, traditional rollback journal modes will likely be faster. > > For transactions in excess of a gigabyte, WAL mode may fail with an I/O > > or disk-full error. > > It is recommended that one of the rollback journal modes be used for > > transactions larger than a few dozen megabytes." > > - sqlite.org/wal.html > > > > > > On the other hand, I've read anecdotal reports from users on this list > > who are using WAL mode with large databases (10s of gigabytes). > > Is wal.html a bit out of date? > > What exactly is meant by "may fail with an I/O or disk-full error"? Is > > this just saying that if your WAL file grows larger than your available > > disk space, you're out of luck? > > > > I'm very interested in the concurrency benefits of WAL mode, but I want > > to be sure it's a safe choice. > > > > Thanks! > > Aemon > > _______________________________________________ > > sqlite-users mailing list > > [email protected] > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- D. Richard Hipp [email protected] _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
