Nikolaus, I've traced your application a bit (with SQLite 3.6.18 sources) and it looks like SQLite does some nasty thing nobody in this thread expected. For some reason while doing first delete SQLite actually commits transaction and degrades lock to SHARED. Then of course second delete cannot be executed because update has already PENDING lock. That's pretty strange and indeed reading sources of sqlite3VdbeHalt I didn't find any condition for committing other than successfulness of the statement. Maybe somebody somewhere forgot to set autocommit to 0 when select started executing?
Dan, can you shed some light on this strange behavior? Pavel On Wed, Aug 25, 2010 at 10:39 AM, Nikolaus Rath <nikol...@rath.org> wrote: > Hi, > > I only saw http://article.gmane.org/gmane.comp.db.sqlite.general/58835, > was there anything else? > > -Nikolaus > > > Gerry Snyder <mesmerizerfan-re5jqeeqqe8avxtiumw...@public.gmane.org> writes: >> Er, did you not see Dan Kennedy's comments a fed days ago?? >> >> On 8/24/10, Nikolaus Rath <nikolaus-bth8mxji...@public.gmane.org> wrote: >>> Nikolaus Rath >>> <nikolaus-bth8mxji4b0-xmd5yjdbdmrexy1tmh2...@public.gmane.org> writes: >>>> Still no one able to clarify the issues raised in this thread? >>>> >>>> Let me try to summarize what I still don't understand: >>>> >>>> - Will SQLite acquire and release an EXCLUSIVE lock while keeping a >>>> SHARED lock if one executes a UPDATE query with one cursor while a >>>> different cursor is in the middle of a SELECT query, >>>> >>>> -or- >>>> >>>> will the EXCLUSIVE lock be held until the SELECT query finishes? >>>> >>>> - Is there a way to prevent SQLite from keeping the SHARED lock >>>> while waiting for an EXCLUSIVE lock if doing so would result in a >>>> deadlock (because another connection holding a SHARED lock needs to >>>> get an EXCLUSIVE lock before it can release the SHARED lock)? >>> >>> >>> Hmm. Still no answer. But thanks to Simon I know at least that some >>> people are reading this thread :-). >>> >>> >>> So different question: does anyone know how to get this thread to the >>> attention of an SQLite developer who might be able to help? >>> >>> >>> Best, >>> >>> -Nikolaus >>> >>> -- >>> »Time flies like an arrow, fruit flies like a Banana.« >>> >>> PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users-czdrofg0bjidnm+yrof...@public.gmane.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >> >> -- >> Sent from my mobile device >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users-czdrofg0bjidnm+yrof...@public.gmane.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > -Nikolaus > > -- > »Time flies like an arrow, fruit flies like a Banana.« > > PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C > _______________________________________________ > 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
