Re: Removing unneeded self joins
Tom Lane <tgl@sss.pgh.pa.us>
Commits
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
Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru> writes: > There is a join optimization we don't do -- removing inner join of a > table with itself on a unique column. Such joins are generated by > various ORMs, so from time to time our customers ask us to look into > this. Most recently, it was discussed on the list in relation to an > article comparing the optimizations that some DBMS make [1]. This is the sort of thing that I always wonder why the customers don't ask the ORM to stop generating such damfool queries. Its *expensive* for us to clean up after their stupidity; almost certainly, it would take far fewer cycles, net, for them to be a bit smarter in the first place. regards, tom lane