On Fri, 2009-01-09 at 11:20 +0000, Simon Riggs wrote: > On Fri, 2009-01-09 at 12:33 +0200, Heikki Linnakangas wrote: > > Simon Riggs wrote: > > > On Thu, 2009-01-08 at 15:50 -0500, Tom Lane wrote: > > >> Simon Riggs <si...@2ndquadrant.com> writes: > > >>> On Thu, 2009-01-08 at 22:31 +0200, Heikki Linnakangas wrote: > > >>>> When a backend dies with FATAL, it writes an abort record before > > >>>> exiting. > > >>>> > > >>>> (I was under the impression it doesn't until few minutes ago myself, > > >>>> when I actually read the shutdown code :-)) > > >>> Not in all cases; keep reading :-) > > >> If it doesn't, that's a bug. A FATAL exit is not supposed to leave the > > >> shared state corrupted, it's only supposed to be a forcible session > > >> termination. Any open transaction should be rolled back. > > > > > > Please look back at the earlier discussion we had on this exact point: > > > http://archives.postgresql.org/pgsql-hackers/2008-09/msg01809.php > > > > I think the running-xacts list we dump to WAL at every checkpoint is > > enough to handle that. Just treat the dead transaction as in-progress > > until the next running-xacts record. It's presumably extremely rare to > > have a process die with FATAL, and not write an abort record. > > I agree, but I'll wait for Tom to speak further.
OK, will proceed without this. Time is pressing. Heikki and I both agree that FATAL errors that fail to write abort records are rare and an acceptable problem in real usage. If they do occur, their nuisance factor is short-lived because of measures taken within the patch. Hot Standby does not *rely* upon there always an abort record for FATAL errors, so we cannot reasonably say the current design would be "unacceptably fragile" as I had once thought. So based upon that, out comes the slotid concept and luckily much of the cruftier aspects of the patch. Less code, probably fewer bugs. Good thing. I will produce a new v7 with those changes and merge the changes for v6b also, so we can begin review again from there. Hi ho, hi ho... -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
