On Mon, Dec 17, 2012 at 04:59:03PM -0600, Percy Wegmann wrote:
Dear MonetDB Team,
We're starting to exercise our MonetDB installation more heavily now and I've run into a strange issue where I get an occasional "COMMIT: failed" message.
It seems that the conditions required to produce this are:
- Concurrently inserting into two different tables - At the same time, issuing a SELECT COUNT(*) against either of those tables
I've logged a bug with more detailed information, including a Java test case:
http://bugs.monetdb.org/show_bug.cgi?id=3210
I'm only just starting my investigation, but I suspect that COUNT(*) may be the culprit, since other selects like SELECT * don't seem to have this problem.
Does this ring any bells? Are there any special optimizations for COUNT(*) that bypass the underlying BAT and/or have side effects on some shared table somewhere that could be causing a concurrency violation?
Thanks,
Percy We fixed a problem today which looks very similar too yours. Could you verify if the fixes checked in to the Oct2012 and Feb2013 branches also solve your problem? Niels
--
Percy Wegmann +1 512 637 8500 ext 148
_______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list
-- Niels Nes, Centrum Wiskunde & Informatica (CWI) Science Park 123, 1098 XG Amsterdam, The Netherlands room L3.14, phone ++31 20 592-4098 sip:4098@sip.cwi.nl url: http://www.cwi.nl/~niels e-mail: Niels.Nes@cwi.nl _______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list