On Fri, Dec 2, 2011 at 2:15 AM, Sreekumar TP <sreekumar...@gmail.com> wrote:
> There is another reader but sharing the same connection. So checkpoint > process cannot be blocked by another reader. > The other reader doesn't have to be active - it merely needs to be holding open a read transaction. Perhaps you have failed to run sqlite3_reset() or sqlite3_finalize() on one or more of the statements from the reader. If you run "PRAGMA wal_checkpoint(RESTART)" then the SQLite connection running that pragma will block until all readers and writers clear and the checkpoint can run to completion - to the point of resetting the WAL file. If that pragma then blocks forever, then you know you have a stuck transaction somewhere. > > > On Thu, Dec 1, 2011 at 8:54 PM, Yves Goergen <nospam.l...@unclassified.de > >wrote: > > > On 01.12.2011 18:58 CE(S)T, Sreekumar TP wrote: > > > During the measurement of manual checkpoint times, I see the following > > > behaviour - > > > > > > # of WAL frames checkpointed is over 1000 > > > size of DB has not changed after checkpoint.(measured using fstat) > > > Time for the checkpoint if around 500 ms. > > > > > > Why is it that eventhough 1000+ frames are checkpointed, the DB size > has > > > not increased ? > > > All records inserted are new and unique records and insertions start > from > > > empty database. > > > > Could it be that the pages were not actually written to the database > > because there was a reader lock on them? Did any other process access > > the database (and thus hold any locks) while you did the checkpointing? > > > > (Wild guess. I've only learned about WAL and started using it yesterday. > > I've read the whole WAL documentation page [1] though.) > > > > [1] http://sqlite.org/wal.html > > > > -- > > Yves Goergen "LonelyPixel" <nospam.l...@unclassified.de> > > Visit my web laboratory at http://beta.unclassified.de > > _______________________________________________ > > 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 > -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
