On Tue, Aug 10, 2010 at 11:35:48PM -0700, John R Pierce wrote: > We've got an app, I don't know all the details of the schema > offhand, but its using date partitioned tables, its heavily > multithreaded and processing continuous events... Under load, > production (overseas) is getting a SQL deadlock... > > Process 20333: DROP table data_details_20100718 > Process 20333 waits for AccessExclusiveLock on relation 29609 of > database 16384; blocked by process 20307. > > Process 20307: select * from data_daily where f1 =$1 and f2=$2 and > f3=$3 and f4=$4 and ... > Process 20307 waits for AccessShareLock on relation 28523 of > database 16384; blocked by process 20333. > > I'm -assuming- that the table being dropped is a partition of the > other table. I've asked the developers (my coworkers) to confirm, > and for any details of how they are doing the partitions. That seems super likely, given its name and the fact that it's being dropped. > does anyone have any suggestions for what to look for, or what sort > of common partition management mistakes in the application could > lead to this sort of deadlock? DDL is a "don't do it at peak load" event. More realistically, it's more like a "down time" event. Maybe when we have "real" partitioning... Cheers, David. -- David Fetter <david@xxxxxxxxxx> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@xxxxxxxxx iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
