Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-04 Thread Tom Lane
Josh Berkus writes: >> And your point is? The design center for the current setup is maybe 5 >> or 10 partitions. We didn't intend it to be used for more partitions >> than you might have spindles to spread the data across. > Where did that come from? It certainly wasn't anywhere when the feat

Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-04 Thread Joshua D. Drake
On Mon, 2010-10-04 at 11:34 -0700, Josh Berkus wrote: > > And your point is? The design center for the current setup is maybe 5 > > or 10 partitions. We didn't intend it to be used for more partitions > > than you might have spindles to spread the data across. > > Where did that come from? Yea

Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-04 Thread Josh Berkus
> And your point is? The design center for the current setup is maybe 5 > or 10 partitions. We didn't intend it to be used for more partitions > than you might have spindles to spread the data across. Where did that come from? It certainly wasn't anywhere when the feature was introduced. Simo

Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-01 Thread Tom Lane
Josh Berkus writes: >> [ shrug ... ] We do not promise that the current partitioning scheme >> scales to the number of partitions where this is likely to be an >> interesting concern. > Actually, you can demonstrate pretty significant response time delays on > only 50 partitions. And your point

Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-01 Thread Josh Berkus
> [ shrug ... ] We do not promise that the current partitioning scheme > scales to the number of partitions where this is likely to be an > interesting concern. Actually, you can demonstrate pretty significant response time delays on only 50 partitions. > We're talking "wasted effort on a dead-

Re: [PERFORM] Issue for partitioning with extra check constriants

2010-10-01 Thread Tom Lane
Josh Berkus writes: > The issue is this: when a partitioned table is evaluated by the planner > for constraint exclusion, it evaluates ALL check constraints on each > partition, regardless of whether or not they include a referenced column > in the query (and whether or not they relate to partitio

[PERFORM] Issue for partitioning with extra check constriants

2010-10-01 Thread Josh Berkus
Simon, Greg, etc., Just barked my nose against a major performance issue with CE & partitioning, and was wondering if anyone had poked at it. The issue is this: when a partitioned table is evaluated by the planner for constraint exclusion, it evaluates ALL check constraints on each partition, reg