Horton

Re: [Proposal] Allow users to specify multiple tables in VACUUM commands

Nathan Bossart <bossartn@amazon.com>

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From: "Bossart, Nathan" <bossartn@amazon.com>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, "David G. Johnston" <david.g.johnston@gmail.com>, Robert Haas <robertmhaas@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2017-09-05T17:36:46Z
Lists: pgsql-hackers 
On 9/4/17, 8:16 PM, "Michael Paquier" <michael.paquier@gmail.com> wrote:
> So vacuum_multiple_tables_v14.patch is good for a committer in my
> opinion. With this patch, if the same relation is specified multiple
> times, then it gets vacuum'ed that many times. Using the same column
> multi-times results in an error as on HEAD, but that's not a new
> problem with this patch.

Thanks!

> So I would tend to think that the same column specified multiple times
> should cause an error, and that we could let VACUUM run work N times
> on a relation if it is specified this much. This feels more natural,
> at least to me, and it keeps the code simple.

I think that is a reasonable approach.  Another option I was thinking
about was to de-duplicate only the individual column lists.  This
alternative approach might be a bit more user-friendly, but I am
beginning to agree with you that perhaps we should not try to infer
the intent of the user in these "duplicate" scenarios.

I'll work on converting the existing de-duplication patch into
something more like what you suggested.

Nathan

Commits

  1. Allow multiple tables to be specified in one VACUUM or ANALYZE command.

  2. Give a better error for duplicate entries in VACUUM/ANALYZE column list.

  3. Reject ANALYZE commands during VACUUM FULL or another ANALYZE.