Horton

Re: removal of dangling temp tables

Robert Haas <robertmhaas@gmail.com>

View thread View on postgr.es
From: Robert Haas <robertmhaas@gmail.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-12-14T16:48:45Z
Lists: pgsql-hackers 
On Fri, Dec 14, 2018 at 11:29 AM Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> I think the best way to fix this is to call RemoveTempRelations()
> unconditionally at session start (without doing the rest of the temp
> table setup, just the removal.)

That would certainly simplify things.  I think I thought about that as
far back as a734fd5d1c309cc553b7c8c79fba96218af090f7 but it seemed
like a significant behavior change and I wasn't sure that everyone
would like it.  In particular, it adds overhead to backend startup
that, in the case of a large temp schema, could be fairly long.

Nevertheless, I tentatively think that a change like this is a good
idea.  I wouldn't back-patch it, though.

-- 
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.