Horton

Re: [HACKERS] WAL logging problem in 9.4.3?

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Heikki Linnakangas <hlinnaka@iki.fi>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-07-18T13:29:01Z
Lists: pgsql-hackers 
On Wed, Jul 18, 2018 at 9:06 AM, Michael Paquier <michael@paquier.xyz> wrote:
>> What's wrong with the approach proposed in
>> http://postgr.es/m/55AFC302.1060805@iki.fi ?
>
> For back-branches that's very invasive so that seems risky to me
> particularly seeing the low number of complaints on the matter.

Hmm. I think that if you disable the optimization, you're betting that
people won't mind losing performance in this case in a maintenance
release.  If you back-patch Heikki's approach, you're betting that the
committed version doesn't have any bugs that are worse than the status
quo.  Personally, I'd rather take the latter bet.  Maybe the patch
isn't all there yet, but that seems like something we can work
towards.  If we just give up and disable the optimization, we won't
know how many people we ticked off or how badly until after we've done
it.

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

Commits

  1. Add perl2host call missing from a new test file.

  2. Skip WAL for new relfilenodes, under wal_level=minimal.

  3. Revert "Skip WAL for new relfilenodes, under wal_level=minimal."

  4. Back-patch log_newpage_range().

  5. During heap rebuild, lock any TOAST index until end of transaction.

  6. In log_newpage_range(), heed forkNum and page_std arguments.

  7. Back-patch src/test/recovery and PostgresNode from 9.6 to 9.5.

  8. Reduce pg_ctl's reaction time when waiting for postmaster start/stop.

  9. Accelerate end-of-transaction dropping of relations

  10. Redesign the planner's handling of index-descent cost estimation.

  11. Make TRUNCATE do truncate-in-place when processing a relation that was created