Horton

Re: SQL:2011 application time

Paul A Jungwirth <pj@illuminatedcomputing.com>

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From: Paul Jungwirth <pj@illuminatedcomputing.com>
To: Matthias van de Meent <boekewurm+postgres@gmail.com>
Cc: Peter Eisentraut <peter@eisentraut.org>, Robert Haas <robertmhaas@gmail.com>, jian he <jian.universality@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-05-12T15:51:11Z
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 5/12/24 05:55, Matthias van de Meent wrote:
>>   > pg=# CREATE UNIQUE INDEX ON temporal_testing USING gist (id, valid_during);
>>   > ERROR:  access method "gist" does not support unique indexes
>>
>> To me that error message seems correct. The programmer hasn't said anything about the special
>> temporal behavior they are looking for.
> 
> But I showed that I had a GIST index that does have the indisunique
> flag set, which shows that GIST does support indexes with unique
> semantics.
> 
> That I can't use CREATE UNIQUE INDEX to create such an index doesn't
> mean the feature doesn't exist, which is what the error message
> implies.

True, the error message is not really telling the truth anymore. I do think most people who hit this 
error are not thinking about temporal constraints at all though, and for non-temporal constraints it 
is still true. It's also true for CREATE INDEX, since WITHOUT OVERLAPS is only available on the 
*constraint*. So how about adding a hint, something like this?:

ERROR:  access method "gist" does not support unique indexes
HINT: To create a unique constraint with non-overlap behavior, use ADD CONSTRAINT ... WITHOUT OVERLAPS.

Yours,

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