Horton

Re: SQL:2011 application time

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Paul Jungwirth <pj@illuminatedcomputing.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-05-12T00:00:00Z
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 Mon, May 6, 2024 at 11:01 AM jian he <jian.universality@gmail.com> wrote:
>
> On Wed, May 1, 2024 at 12:39 AM Paul Jungwirth
> <pj@illuminatedcomputing.com> wrote:
> >
> > On 4/30/24 09:24, Robert Haas wrote:
> > > Peter, could you have a look at
> > > http://postgr.es/m/47550967-260b-4180-9791-b224859fe63e@illuminatedcomputing.com
> > > and express an opinion about whether each of those proposals are (a)
> > > good or bad ideas and (b) whether they need to be fixed for the
> > > current release?
> >
> > Here are the same patches but rebased. I've added a fourth which is my progress on adding the CHECK
> > constraint. I don't really consider it finished though, because it has these problems:
> >
> > - The CHECK constraint should be marked as an internal dependency of the PK, so that you can't drop
> > it, and it gets dropped when you drop the PK. I don't see a good way to tie the two together though,
> > so I'd appreciate any advice there. They are separate AlterTableCmds, so how do I get the
> > ObjectAddress of both constraints at the same time? I wanted to store the PK's ObjectAddress on the
> > Constraint node, but since ObjectAddress isn't a Node it doesn't work.
> >
>
> hi.
> I hope I understand the problem correctly.
> my understanding is that we are trying to solve a corner case:
> create table t(a int4range, b int4range, primary key(a, b WITHOUT OVERLAPS));
> insert into t values ('[1,2]','empty'), ('[1,2]','empty');
>


but we still not yet address for cases like:
create table t10(a int4range, b int4range, unique (a, b WITHOUT OVERLAPS));
insert into t10 values ('[1,2]','empty'), ('[1,2]','empty');

one table can have more than one temporal unique constraint,
for each temporal unique constraint adding a check isempty constraint
seems not easy.

for example:
CREATE TABLE t (
id int4range,
valid_at daterange,
parent_id int4range,
CONSTRAINT t1 unique (id, valid_at WITHOUT OVERLAPS),
CONSTRAINT t2 unique (parent_id, valid_at WITHOUT OVERLAPS),
CONSTRAINT t3 unique (valid_at, id WITHOUT OVERLAPS),
CONSTRAINT t4 unique (parent_id, id WITHOUT OVERLAPS),
CONSTRAINT t5 unique (id, parent_id WITHOUT OVERLAPS),
CONSTRAINT t6 unique (valid_at, parent_id WITHOUT OVERLAPS)
);
add 6 check isempty constraints for table "t"  is challenging.

so far, I see the challenging part:
* alter table alter column data type does not drop previous check
isempty constraint, and will also add a check isempty constraint,
so overall it will add more check constraints.
* adding more check constraints needs a  way to resolve naming collisions.

Maybe we can just mention that the special 'empty' range value makes
temporal unique constraints not "unique".

also we can make sure that
FOREIGN KEY can only reference primary keys, not unique temporal constraints.
so the unique temporal constraints not "unique" implication is limited.
I played around with it, we can error out these cases in the function
transformFkeyCheckAttrs.