Horton

Re: SQL:2011 application time

Paul A Jungwirth <pj@illuminatedcomputing.com>

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From: Paul Jungwirth <pj@illuminatedcomputing.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Isaac Morland <isaac.morland@gmail.com>, Jeff Davis <pgsql@j-davis.com>, Peter Eisentraut <peter@eisentraut.org>, jian he <jian.universality@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-07-05T19:22:31Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Rename gist stratnum support function

  2. Remove support for temporal RESTRICT foreign keys

  3. Cache NO ACTION foreign keys separately from RESTRICT foreign keys

  4. Fix NO ACTION temporal foreign keys when the referenced endpoints change

  5. Improve whitespace in without_overlaps test

  6. Tests for logical replication with temporal keys

  7. Support for GiST in get_equal_strategy_number()

  8. Make the conditions in IsIndexUsableForReplicaIdentityFull() more explicit

  9. Replace get_equal_strategy_number_for_am() by get_equal_strategy_number()

  10. Improve internal logical replication error for missing equality strategy

  11. Simplify IsIndexUsableForReplicaIdentityFull()

  12. Fix ALTER TABLE / REPLICA IDENTITY for temporal tables

  13. doc: Update pg_constraint.conexclop docs for WITHOUT OVERLAPS

  14. doc: Add PERIOD to ALTER TABLE reference docs

  15. doc: Add WITHOUT OVERLAPS to ALTER TABLE reference docs

  16. Add temporal FOREIGN KEY contraints

  17. Add temporal PRIMARY KEY and UNIQUE constraints

  18. Add stratnum GiST support function

  19. Avoid crashing when a JIT-inlined backend function throws an error.

  20. Revert temporal primary keys and foreign keys

  21. Fix ON CONFLICT DO NOTHING/UPDATE for temporal indexes

  22. Add test for REPLICA IDENTITY with a temporal key

  23. Use half-open interval notation in without_overlaps tests

  24. Use daterange and YMD in without_overlaps tests instead of tsrange.

  25. Rename pg_constraint.conwithoutoverlaps to conperiod

  26. Fix comment on gist_stratnum_btree

  27. Add missing TAP test name

  28. Improve error handling of HMAC computations

  29. Rename functions to avoid future conflicts

Attachments

Here is v35 of this patch series, with a few small changes. I renamed relperiods to 
relwithoutoverlaps, since that is more accurate about what we're counting. (PERIODs come in a later 
patch and we don't need to count them.) Also I cleaned up the branches in psql/pg_dump on version 
now that we're officially on v18.

On 6/28/24 05:18, Robert Haas wrote:
> On Thu, Jun 27, 2024 at 5:56 PM Paul Jungwirth
> <pj@illuminatedcomputing.com> wrote:
>> I did add a relperiods column, but I have a mostly-complete branch here (not included in the
>> patches) that does without. Not maintaining that new column is simpler for sure. The consequence is
>> that the relcache must scan for WITHOUT OVERLAPS constraints on every table. That seems like a high
>> performance cost for a feature most databases won't use. Since we try hard to avoid that kind of
>> thing (e.g. [1]), I thought adding relperiods would be preferred. If that's the wrong tradeoff I can
>> change it.
> 
> I'm sure that you are right that nobody is going to like an extra
> index scan just to find periods. So, suppose we do as you propose and
> add relperiods. In the situation where we are adding the first period
> (or whatever the right term is) to the table, what kind of lock are we
> holding on the table? Conversely, when we drop the last period, what
> kind of lock are we holding on the table? If, hypothetically, both
> answers were AccessExclusiveLock, this might not be too bad, but if
> you say "ShareLock" then we've got a lot of problems; that's not even
> self-exclusive.

This happens when creating a PRIMARY KEY or UNIQUE constraint, so we already have an 
AccessExclusiveLock on the table (whether creating or dropping). If we ever supported CREATE INDEX 
CONCURRENTLY for this, we would need to be careful about where we update the new field, but today we 
don't support that for exclusion constraints.

Rebased to 4b211003ec.

Yours,

-- 
Paul              ~{:-)
pj@illuminatedcomputing.com