From: | "Merlin Moncure" <merlin(dot)moncure(at)rcsonline(dot)com> |
---|---|
To: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: Finding bottleneck |
Date: | 2005-08-22 13:15:10 |
Message-ID: | 6EE64EF3AB31D5448D0007DD34EEB3417DD15D@Herge.rcsinc.local |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
> Bill of Materials Traversal ( ~ 62k records).
>
> ISAM* pg 8.0 pg 8.1 devel delta 8.0->8.1
> running time 63 sec 90 secs 71 secs 21%
> cpu load 17% 45% 32% 29%
> loadsecs** 10.71 40.5 22.72 44%
> recs/sec 984 688 873
> recs/loadsec 5882 1530 2728
>
> *ISAM is an anonymous commercial ISAM library in an optimized server
> architecture (pg smokes the non-optimized flat file version).
> **Loadsecs being seconds of CPU at 100% load.
One thing that might interest you is that the penalty in 8.1 for
stats_command_string=true in this type of access pattern is very high: I
was experimenting to see if the new cpu efficiency gave me enough of a
budget to start using this. This more than doubled the cpu load to
around 70% with a runtime of 82 seconds. This is actually worse than
8.0 :(.
This *might* be a somewhat win32 specific issue. I've had issues with
the stats collector before. Anyways, the feature is a frill so it's not
a big deal.
Merlin
From | Date | Subject | |
---|---|---|---|
Next Message | Jignesh Shah | 2005-08-22 13:47:38 | MemoryContextSwitchTo during table scan? |
Previous Message | Mark Cotner | 2005-08-22 09:29:12 | Re: sustained update load of 1-2k/sec |