Re: [PERFORM] NULLS LAST performance

2011-03-09 Thread Jim Nasby
On Feb 24, 2011, at 3:47 AM, Mathieu De Zutter wrote: > > which will index optimize your sql. Interesting that 'null last' > > fools disallows index usage even when the index was created with > > nullls last as the default. > > The problem is that his query needs to scan the index in DESC order,

Re: [PERFORM] Slow join on partitioned table

2011-03-09 Thread Conor Walsh
On Fri, Mar 4, 2011 at 8:47 AM, Mark Thornton wrote: > It is a temporary table and thus I hadn't thought to analyze it. How should > such tables be treated? Should I analyze it immediately after creation (i.e. > when it is empty), after filling it or ... ? The expected usage is such that > the tem

Re: [PERFORM] Table partitioning problem

2011-03-09 Thread Jim Nasby
On Mar 8, 2011, at 9:45 AM, Samba GUEYE wrote: > I have a problem with table partitioning because i have a foreign key applied > on the partionned table and it throw a constraint violation error during > inserts. > I saw on the manual > (http://www.postgresql.org/docs/8.4/interactive/ddl-inherit

Re: [PERFORM] Query performance with disabled hashjoin and mergejoin

2011-03-09 Thread Robert Haas
On Tue, Mar 8, 2011 at 4:24 PM, Tom Lane wrote: > Robert Haas writes: >> The reason I thought cross-column correlations might be relevant is >> that the bitmap index scan on news_visible_from is quite accurate >> (19976 estimated vs. 19932 actual) and the bitmap index scan on >> news_visible_to i