Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-04-18T19:33:08Z
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.

I wrote:
> Pavan Deolasee <pavan.deolasee@gmail.com> writes:
>> What if we remember the buffers as seen by count_nondeletable_pages() and
>> then just discard those specific buffers instead of scanning the entire
>> shared_buffers again?

> That's an idea.

BTW, before pushing too hard on any of this, we need to think about the
data-corruption hazard that MauMau just reminded us about.  I'm afraid
what we're likely to end up with after the dust settles is worse
performance than today, not better :-(.

https://postgr.es/m/5BBC590AE8DF4ED1A170E4D48F1B53AC@tunaPC

			regards, tom lane