Horton

Re: SQL:2011 application time

Matthias van de Meent <boekewurm+postgres@gmail.com>

View thread
From: Matthias van de Meent <boekewurm+postgres@gmail.com>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: Paul Jungwirth <pj@illuminatedcomputing.com>, jian he <jian.universality@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-11-14T18:14:18Z
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

On Wed, 13 Nov 2024, 11:11 Peter Eisentraut, <peter@eisentraut.org> wrote:
> This conditional is really hard to understand:
>
> +       /*
> +        * The AM must support uniqueness, and the index must in fact be
> unique.
> +        * If we have a WITHOUT OVERLAPS constraint (identified by
> uniqueness +
> +        * exclusion), we can use that too.
> +        */
> +       if ((!indexRel->rd_indam->amcanunique ||
> +               !indexRel->rd_index->indisunique) &&
> +               !(indexRel->rd_index->indisunique &&
> indexRel->rd_index->indisexclusion))
>
> Why can we have a indisunique index when the AM is not amcanunique?  Are
> we using the fields wrong?

I called this issue out earlier this year: amcanunique implies
btree-style uniqueness, and allows CREATE UNIQUE INDEX. However, that
IndexAmRoutine field seems to be ignored for indexes that are created
to back temporal unique constraints, which thus get
indrel->indisunique = true. This causes interesting issues when you
look at the index catalog and errors: there are indexes with
indisunique using gist, but CREATE UNIQUE INDEX USING gist (...)
throws the nice "access method "gist" does not support unique indexes"
error.

It'd be nice if there was a better internal API to describe what types
of uniqueness each index supports, so CREATE UNIQUE INDEX could work
with gist for WITHOUT OVERLAPS, and these WITHOUT OVERLAPS unique
indexes could be attached to primary keys without taking O(>=
tablesize) of effort.

Kind regards,

Matthias van de Meent
Neon (https://neon.tech)