Horton

Re: removal of dangling temp tables

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-12-14T17:48:35Z
Lists: pgsql-hackers 
On Fri, Dec 14, 2018 at 12:27 PM Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> Hmm, I think in the case covered by your commit, that is a session that
> crashes with a few thousands of temp tables, this new patch might cause
> a failure to open a new session altogether.

Oh, good point.  Or if the catalog is corrupted.

> Maybe it'd be better to change temp table removal to always drop
> max_locks_per_transaction objects at a time (ie. commit/start a new
> transaction every so many objects).

We're basically just doing DROP SCHEMA ... CASCADE, so I'm not sure
how we'd implement that, but I agree it would be significantly better.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Have DISCARD ALL/TEMP remove leftover temp tables

  2. Make autovacuum more selective about temp tables to keep

  3. Make autovacuum more aggressive to remove orphaned temp tables

  4. autovacuum: Drop orphan temp tables more quickly but with more caution.