Horton

Re: GUC for cleanup indexes threshold.

Jim Nasby <jim.nasby@bluetreble.com>

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From: Jim Nasby <Jim.Nasby@BlueTreble.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>, Robert Haas <robertmhaas@gmail.com>
Cc: Simon Riggs <simon@2ndquadrant.com>, "Ideriha, Takeshi" <ideriha.takeshi@jp.fujitsu.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Kuntal Ghosh <kuntalghosh.2007@gmail.com>
Date: 2017-02-20T02:35:12Z
Lists: pgsql-hackers 
On 2/19/17 7:56 PM, Masahiko Sawada wrote:
> The half-dead pages are never cleaned up if the ratio of pages
> containing garbage is always lower than threshold. Also in gin index
> the pending list is never cleared, which become big problem. I guess
> that we should take action for each type of indexes.

What worries me is that each AM is going to have a different notion of 
what needs to happen to support this. That indicates that trying to 
handle this at the vacuum level is not a good idea.

I think it would be wiser to add support for skipping scans to the AM 
API instead. That also means you don't have to add support for this to 
every index type to start with.
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
855-TREBLE2 (855-873-2532)

Commits

  1. Fix upper limit for vacuum_cleanup_index_scale_factor

  2. Increase upper limit for vacuum_cleanup_index_scale_factor

  3. Fixes for vacuum_cleanup_index_scale_factor GUC option

  4. Skip full index scan during cleanup of B-tree indexes when possible