Re: Info about concurrent sequential scans - Mailing list pgsql-general

From Bruce Momjian
Subject Re: Info about concurrent sequential scans
Date
Msg-id 201002221953.o1MJr7q04365@momjian.us
Whole thread Raw
In response to Info about concurrent sequential scans  (Daniele Varrazzo <daniele.varrazzo@gmail.com>)
List pgsql-general
Daniele Varrazzo wrote:
> Hello,
>
> at Prato PgDay in 2007 I remember hearing in a speech about a (then
> yet to come) "seqscan piggyback" feature, allowing concurrent
> sequential scans to use the same disk reads. I've now googled for info
> about this feature, but I found nothing conclusive (e.g. [1], [2] -
> which I don't know where is linked).
>
> So I'd like to know:
>
> is this feature currently implemented (I'm specifically interested in PG 8.3)?
> Is there any prerequisite needed to benefit from it (config setting,
> query characteristic, etc.)?
> Is there any feedback showing the feature kicking in (e.g. an explain
> analyze output, log, etc.)?

The feature is called 'synchronize_seqscans' and was implemented in
Postgres 8.3.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com
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  + If your life is a hard drive, Christ can be your backup. +

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