Re: Making Vars outer-join aware

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ted Yu <yuzhihong@gmail.com>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>, "Finnerty, Jim" <jfinnert@amazon.com>
Date: 2022-12-23T21:09:16Z
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. Re-allow INDEX_VAR as rt_index in ChangeVarNodes().

  2. Fix thinkos in have_unsafe_outer_join_ref; reduce to Assert check.

  3. Invent "join domains" to replace the below_outer_join hack.

  4. Do assorted mop-up in the planner.

  5. Make Vars be outer-join-aware.

  6. Invent "multibitmapsets", and use them to speed up antijoin detection.

  7. Add basic regression tests for semi/antijoin recognition.

  8. Improve performance of adjust_appendrel_attrs_multilevel.

  9. Refactor addition of PlaceHolderVars to joinrel targetlists.

  10. Use an explicit state flag to control PlaceHolderInfo creation.

  11. Make PlaceHolderInfo lookup O(1).

Ted Yu <yuzhihong@gmail.com> writes:
> For v8-0012-invent-join-domains.patch, in `distribute_qual_to_rels`, it
> seems that `pseudoconstant` and `root->hasPseudoConstantQuals` carry the
> same value.
> Can the variable `pseudoconstant` be omitted ?

Surely not.  'pseudoconstant' tells whether the current qual clause
is pseudoconstant.  root->hasPseudoConstantQuals remembers whether
we have found any pseudoconstant qual in the query.

			regards, tom lane