Re: WIP patch for latestCompletedXid method of computing snapshot xmax - Mailing list pgsql-hackers

From Josh Berkus
Subject Re: WIP patch for latestCompletedXid method of computing snapshot xmax
Date
Msg-id 200709081418.35059.josh@agliodbs.com
Whole thread Raw
In response to Re: WIP patch for latestCompletedXid method of computing snapshot xmax  (Markus Schiltknecht <markus@bluegap.ch>)
Responses Re: WIP patch for latestCompletedXid method of computing snapshot xmax
Re: WIP patch for latestCompletedXid method of computing snapshot xmax
List pgsql-hackers
Markus,

> I've just completed two dbt2 test runs on a mid-level system, with 4GB
> RAM and a 7 disk SATA RAID 1+0 w/ BBU. Once with code as of 2007/09/05
> 18:00 (which is *before* the first lazy xid commit) and once with cvs
> HEAD (2007/09/08  +latestCompletedXid.patch.

Hmmm.  Your results are withing the margin of error for DBT2, so they show no 
real difference.  What we need for this is a heavy-read workload, though; on 
a workload like DBT2 (which is mostly writes) I wouldn't expect lazy-XID to 
help much.

I'll see if I can find something appropriate.  Maybe Jan's TPC-W 
implementation?

-- 
Josh Berkus
PostgreSQL @ Sun
San Francisco


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