| From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
|---|---|
| To: | Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: RAM-only temporary tables |
| Date: | 2008-11-06 16:22:08 |
| Message-ID: | 20081106162208.GH5520@alvh.no-ip.org |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Kevin Grittner wrote:
> It sounds like you were counting the 8kB pages pushed from the
> PostgreSQL cache to the OS cache, and I was counting the 1kB blocks
> pushed from the OS cache to the RAID controller cache. By watching
> vmstat results after pushing this to a more-or-less steady state, I
> was probably picking up the results of autovacuum runs, but multiple
> writes to a single page were often combined by the OS. If we match,
> it's really just a coincidence.
I was counting WAL inserts actually, so "logical database operations".
I left out "storage" items (filesystem actions), so it was mainly just
catalog changes.
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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