On Fri, Feb 10, 2012 at 9:01 AM, Marc L. Allen <mlal...@outsitenetworks.com>wrote:
> I'm not sure I'm even following how this scenario can happen. Doesn't > App1 have a Shared lock on the DB? Doesn't App2 require an Exclusive lock > before it can update something? > The OP is running in WAL mode. Different rules apply. In WAL mode, you can have multiple simultaneous readers concurrently with a single writer. And the readers all see (possibly different) snapshots of the database from the point in time where their read transaction was first started. > > When given the initial scenario, I thought that Step 5 would block waiting > for App1 to finalize. > > > -----Original Message----- > > From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users- > > boun...@sqlite.org] On Behalf Of Simon Slavin > > Sent: Friday, February 10, 2012 8:55 AM > > To: General Discussion of SQLite Database > > Subject: Re: [sqlite] Database locked in multi process scenario > > > > > > On 10 Feb 2012, at 1:52pm, Sreekumar TP wrote: > > > > > In the real code, there is no sleep/wait or pause. It so happens that > > > the write of the app2 is scheduled in between. > > > > > > What you are suggesting is that at any point of time only one process > > > can have a transaction open in a database? > > > > I understand your question but I don't know enough of the internals of > > SQLite to answer it. Also, I'm not sure how the time between the first > > _step() and the step which returns 'no more data' resembles a > > transaction. I hope someone who knows more than I do will contribute. > > > > 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 > -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
