Re: Synchronized scans - Mailing list pgsql-patches

From Gregory Stark
Subject Re: Synchronized scans
Date
Msg-id 87vedx7xiw.fsf@oxford.xeocode.com
Whole thread Raw
In response to Re: Synchronized scans  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Synchronized scans  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-patches
"Tom Lane" <tgl@sss.pgh.pa.us> writes:

> The vacuum-cost-limit issue may be sufficient reason to kill this idea;
> not sure.

We already have a much higher cost for blocks that cause i/o than blocks which
don't. I think if we had zero cost for blocks which don't cause i/o it would
basically work unless the sleep time was so large that the other scans managed
to cycle through the entire ring in that time.

--
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com


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