Hello Richard, That's what I was hoping to hear. Thanks,
Wednesday, November 30, 2011, 2:01:46 PM, you wrote: RH> On Wed, Nov 30, 2011 at 1:39 PM, Teg <t...@djii.com> wrote: >> Hello Richard, >> >> Appreciate the reply but, it doesn't address my question (unless I'm >> missing something). I get that checkpointing doesn't reduce the size >> of the WAL. Assuming a single writer and no readers, If I perform a >> transaction that generates a WAL file. Does it eventually get deleted >> when I finish my transaction? How about when I close the DB? RH> The wal file persists until the last connection to the database closes, RH> then the wal file is deleted. Meanwhile, the wal file is recycled (meaning RH> that SQLite starts reusing it again from the beginning) after each RH> successful checkpoint. Checkpoints are automatically run by transactions RH> that cause the size of the wal file to exceed 1000 pages (though this can RH> be tuned or disabled if desired). RH> For most applications, WAL mode just works and you don't have to think RH> about how. >> I haven't >> updated to the most current SQlite because I was unclear about how >> persistent the WAL files actually were. Some of my DB's are 30 GB+. I >> don't mind the WAL's growing as long as they go away when the process >> is finished. >> >> >> >> >> >> Wednesday, November 30, 2011, 1:10:50 PM, you wrote: >> >> RH> On Wed, Nov 30, 2011 at 1:04 PM, Teg <t...@djii.com> wrote: >> >> >> Hello Richard, >> >> >> >> When does the WAL get trimmed down? If my transaction completes, does >> >> the WAL file get deleted? I've seen the WAL grow to 4 times my actual >> >> DB size so, I don't really want 160 Gigs of WAL hanging out when the >> >> process that generated it is only run once a month. >> >> >> >> RH> SQLite starts writing the WAL file from the beginning again on the >> first >> RH> write transaction that follows a checkpoint that ran to completion and >> RH> where there are no readers using the WAL file. A checkpoint will >> normally >> RH> run to completion if there are no readers still using prior >> transactions. >> RH> If there are readers on prior transactions, then the checkpoint cannot >> run >> RH> to completion since that would delete content out from under the >> readers. >> >> >> >> >> >> >> >> -- >> Best regards, >> Teg mailto:t...@djii.com >> >> -- Best regards, Teg mailto:t...@djii.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
