Horton

Re: WAL logging problem in 9.4.3?

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: "Todd A. Cook" <tcook@blackducksoftware.com>, Tom Lane <tgl@sss.pgh.pa.us>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2015-07-22T06:45:47Z
Lists: pgsql-hackers 
On 2015-07-21 21:37:41 +0200, Martijn van Oosterhout wrote:
> On Tue, Jul 21, 2015 at 02:24:47PM -0400, Todd A. Cook wrote:
> > Hi,
> > 
> > This thread seemed to trail off without a resolution.  Was anything done?
> 
> Not that I can tell.

Heikki and I had some in-person conversation about it at a conference,
but we didn't really find anything we both liked...

>I was the original poster of this thread. We've
> worked around the issue by placing a CHECKPOINT command at the end of
> the migration script.  For us it's not a performance issue, more a
> correctness one, tables were empty when they shouldn't have been.

If it's just correctness, you could just use wal_level = archive.

> I'm hoping a fix will appear in the 9.5 release, since we're intending
> to release with that version.  A forced checkpoint every now and them
> probably won't be a serious problem though.

We're imo going to have to fix this in the back branches.

Andres

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