Re: POC, WIP: OR-clause support for indexes

Peter Geoghegan <pg@bowt.ie>

From: Peter Geoghegan <pg@bowt.ie>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Alena Rybakina <a.rybakina@postgrespro.ru>, Alexander Korotkov <aekorotkov@gmail.com>, jian he <jian.universality@gmail.com>, pgsql-hackers@postgresql.org, Marcos Pegoraro <marcos@f10.com.br>, teodor@sigaev.ru, Andrei Lepikhov <a.lepikhov@postgrespro.ru>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Peter Eisentraut <peter@eisentraut.org>, Ranier Vilela <ranier.vf@gmail.com>

Date: 2024-06-24T17:54:10Z

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 →

Make group_similar_or_args() reorder clause list as little as possible
- 775a06d44c04 18.0 landed
Allow usage of match_orclause_to_indexcol() for joins
- 627d63419e22 18.0 landed
Skip not SOAP-supported indexes while transforming an OR clause into SAOP
- 5bba0546eecb 18.0 landed
Remove the wrong assertion from match_orclause_to_indexcol()
- d4d11940df94 18.0 landed
Teach bitmap path generation about transforming OR-clauses to SAOP's
- ae4569161a27 18.0 landed
Transform OR-clauses to SAOP's during index matching
- d4378c0005e6 18.0 landed
Fix the value of or_to_any_transform_limit in postgresql.conf.sample
- 2af75e117478 17.0 landed
Transform OR clauses to ANY expression
- 72bd38cc99a1 17.0 landed
MergeAttributes code deduplication
- 64444ce071f6 17.0 cited
SEARCH and CYCLE clauses
- 3696a600e229 14.0 cited
Improve estimation of OR clauses using extended statistics.
- 25a9e54d2db3 14.0 cited
Teach btree to handle ScalarArrayOpExpr quals natively.
- 9e8da0f75731 9.2.0 cited
Revise collation derivation method and expression-tree representation.
- b310b6e31ce5 9.1.0 cited
Instead of trying to force WHERE clauses into CNF or DNF normal form,
- 9888192fb773 8.0.0 cited

On Mon, Jun 24, 2024 at 1:46 PM Peter Geoghegan <pg@bowt.ie> wrote:
> BTW, did you know MySQL has long supported the latter? It has a <=>
> operator, which is basically a non-standard spelling of IS NOT
> DISTINCT FROM. Importantly, it is indexable, whereas right now
> Postgres doesn't support indexing IS NOT DISTINCT FROM. If you're
> interested in working on this problem within the scope of this patch,
> or some follow-up patch, I can take care of the nbtree side of things.

To be clear, I meant that we could easily support "where mycol = 5 OR
mycol IS NULL" and have nbtree handle that efficiently, by making it a
SAOP internally. Separately, we could also make IS NOT DISTINCT FROM
indexable, though that probably wouldn't need any work in nbtree.

-- 
Peter Geoghegan