On Thu, May 15, 2014 at 9:35 AM, Scott Marlowe <scott.marl...@gmail.com>wrote:
> OK so we have a query that does OK in 8.4, goes to absolute crap in > 9.2 and then works great in 9.3. Thing is we've spent several months > regression testing 9.2 and no time testing 9.3, so we can't just "go > to 9.3" in an afternoon. But we might have to. 9.2 seems hopelessly > broken here. > > The query looks something like this: > > SELECT COUNT(*) FROM u, ug > WHERE u.ugid = ug.id > AND NOT u.d > AND ug.somefield IN (SELECT somefunction(12345)); > > In 8.4 we get this plan http://explain.depesz.com/s/r3hF which takes ~5ms > In 9.2 we get this plan http://explain.depesz.com/s/vM7 which takes ~10s > In 9.3 we get this plan http://explain.depesz.com/s/Wub which takes > ~0.35ms > Based on the actual row counts given in the seq scan on u, , in 9.2, u contains millions of rows. In 9.3, it contains zero rows. > > The data sets are identical, the schemas are identical. Please double check that. Cheers, Jeff
