Re: Removing unneeded self joins

Andrei Lepikhov <a.lepikhov@postgrespro.ru>

From: Andrey Lepikhov <a.lepikhov@postgrespro.ru>

To: Greg Stark <stark@mit.edu>

Cc: Andres Freund <andres@anarazel.de>, Ronan Dunklau <ronan.dunklau@aiven.io>, Laurenz Albe <laurenz.albe@cybertec.at>, Hywel Carver <hywel@skillerwhale.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2022-05-13T05:07:47Z

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 →

Remove GUC_NOT_IN_SAMPLE from enable_self_join_elimination
- 717d0e8dd945 18.0 landed
Put enable_self_join_elimination into postgresql.conf.sample
- c2d329260cd8 18.0 landed
Get rid of ojrelid local variable in remove_rel_from_query()
- e167191dc146 18.0 landed
Implement Self-Join Elimination
- fc069a3a6319 18.0 cited
Revert: Remove useless self-joins
- d1d286d83c0e 17.0 landed
Replace lateral references to removed rels in subqueries
- 466979ef031a 17.0 landed
Replace relids in lateral subquery parse tree during SJE
- 489072ab7a9e 17.0 landed
Forbid SJE with result relation
- 8c441c082797 17.0 landed
Fix misuse of RelOptInfo.unique_for_rels cache by SJE
- 30b4955a4668 17.0 landed
Replace the relid in some missing fields during SJE
- a7928a57b9f0 17.0 landed
Revert 56-bit relfilenode change and follow-up commits.
- a448e49bcbe4 16.0 cited
Stabilize timetz test across DST transitions.
- 4a071afbd056 14.0 cited
Speed up finding EquivalenceClasses for a given set of rels
- 3373c7155350 13.0 cited
Fix mark-and-restore-skipping test case to not be a self-join.
- 24d08f3c0a1f 12.0 landed

Attachments

v33-0001-Remove-self-joins.patch (text/x-patch) patch v33-0001
delta.txt (text/plain)

New version of the feature.
Here a minor bug with RowMarks is fixed. A degenerated case is fixed, 
when uniqueness of an inner deduced not from join quals, but from a 
baserestrictinfo clauses 'x=const', where x - unique field.
Code, dedicated to solve second issue is controversial, so i attached 
delta.txt for quick observation.
Maybe we should return to previous version of code, when we didn't split 
restriction list into join quals and base quals?

-- 
Regards
Andrey Lepikhov
Postgres Professional