Horton

Re: [HACKERS] Vacuum: allow usage of more than 1GB of work mem

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Claudio Freire <klaussfreire@gmail.com>
Cc: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Thomas Munro <thomas.munro@enterprisedb.com>, Stephen Frost <sfrost@snowman.net>, Michael Paquier <michael.paquier@gmail.com>, Daniel Gustafsson <daniel@yesql.se>, Andres Freund <andres@anarazel.de>, Masahiko Sawada <sawada.mshk@gmail.com>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, Anastasia Lubennikova <lubennikovaav@gmail.com>, PostgreSQL-Dev <pgsql-hackers@postgresql.org>
Date: 2018-02-07T22:57:30Z
Lists: pgsql-hackers 
Claudio Freire wrote:

> - vacuum test on its own parallel group

Hmm, this solution is not very friendly to the goal of reducing test
runtime, particularly since the new test creates a nontrivial-sized
table.  Maybe we can find a better alternative.  Can we use some wait
logic instead?  Maybe something like grab a snapshot of running VXIDs
and loop waiting until they're all gone before doing the vacuum?

Also, I don't understand why pg_relation_size() is not a better solution
to determining the table size compared to explain.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Prefetch blocks during lazy vacuum's truncation scan

  2. Explain unaccounted for space in pgstattuple.