Horton

Re: reloption to prevent VACUUM from truncating empty pages at the end of relation

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: "Jamison, Kirk" <k.jamison@jp.fujitsu.com>, "Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, 'Amit Kapila' <amit.kapila16@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Fujii Masao <masao.fujii@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2019-02-01T08:26:58Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add TRUNCATE parameter to VACUUM.

  2. Add vacuum_truncate reloption.

  3. Allow VACUUM to be run with index cleanup disabled.

On Fri, Feb 01, 2019 at 09:11:50AM +0100, Laurenz Albe wrote:
> Jamison, Kirk wrote:
>> I wonder if there is a better reloption name for
>> shrink_enabled. (truncate_enabled, vacuum_enabled? Hmm. No?)  
>> On the other hand, shrink_enabled seems to describe well what it's
>> supposed to do when vacuuming tables.  Besides there's a
>> similarly-named autovacuum_enabled option.
> 
> I like "shrink_enabled".
> 
> It may sound weird in the ears of PostgreSQL hackers, but will make
> sense to users.
> 
> Perhaps "vacuum_shrink_enabled" would be even better.

Naming it just vacuum_truncate and autovacuum_truncate (with aliases
for toast and such), looks more natural to me.  "shrink" is not a term
used in the code at all to describe this phase of vacuuming, and this
option talks mainly to people who are experts in PostgreSQL internals
in my opinion.
--
Michael