Horton

Re: Postgres 11 release notes

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Bruce Momjian <bruce@momjian.us>
Cc: pgsql-hackers@lists.postgresql.org, Adrien Nayrat <adrien.nayrat@anayrat.info>
Date: 2018-08-25T19:17:17Z
Lists: pgsql-hackers 
Hi,

On 2018-08-25 14:47:20 -0400, Bruce Momjian wrote:
> Well, our normal logical is whether the average user would adjust their
> behavior based on this change, or whether it is user visible.  I thought
> it was a contrived-enough query that this was not the case, but I would
> be interested to hear what others think.

I think that's less "our" logic and more yours, that has become
established because you've done most of the major release notes for a
long time. I'm not trying to say that that's wrong or anything, just
that a lot of those principles grew organically without explicit
decisions.

I also think that the need of userbase have shifted - it used to be that
a lot more people couldn't migrate to PG for lack of features, but these
days we have a much larger userbase that has to migrate from version to
version on a regular basis.

Planner changes, in my experience, are *the* major hurdle in doing so
(leaving aside things like the 8.3 casting changes), because they have
the potential to drastically change performance. In a largely
unpredictable way.  So one of the first things you do after encountering
an issue while testing an issue during a migration, is to look through
the release notes whether that query could be affected by a documented
change.

Greetings,

Andres Freund

Commits

  1. doc: update PG 11 release notes

  2. Fix misspelled pg_trgm contrib name in PostgreSQL 11 release notes

  3. Doc: clarify release note text about v11's new window function features.

  4. Improve wording of release notes item

  5. Fix typos in release notes

  6. Doc: preliminary list of PG11 major features.

  7. Make numeric power() handle NaNs according to the modern POSIX spec.

  8. Various improvements of skipping index scan during vacuum technics

  9. Revert back-branch changes in power()'s behavior for NaN inputs.

  10. Avoid wrong results for power() with NaN input on more platforms.

  11. Avoid wrong results for power() with NaN input on some platforms.

  12. Skip full index scan during cleanup of B-tree indexes when possible

  13. Rewrite the code that applies scan/join targets to paths.

  14. Postpone generate_gather_paths for topmost scan/join rel.

  15. Add casts from jsonb

  16. Make plpgsql use its DTYPE_REC code paths for composite-type variables.

  17. Don't allow VACUUM VERBOSE ANALYZE VERBOSE.

  18. Pass InitPlan values to workers via Gather (Merge).

  19. Account for the effect of lossy pages when costing bitmap scans.

  20. Allow no-op GiST support functions to be omitted.

  21. Rearm statement_timeout after each executed query.

  22. Push limit through subqueries to underlying sort, where possible.