Horton

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

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Andrei Lepikhov <a.lepikhov@postgrespro.ru>
Cc: Alena Rybakina <a.rybakina@postgrespro.ru>, Alexander Korotkov <aekorotkov@gmail.com>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@postgresql.org, Peter Geoghegan <pg@bowt.ie>, "Finnerty, Jim" <jfinnert@amazon.com>, Marcos Pegoraro <marcos@f10.com.br>, teodor@sigaev.ru, Ranier Vilela <ranier.vf@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Peter Eisentraut <peter@eisentraut.org>
Date: 2024-02-16T12:54:16Z
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. Make group_similar_or_args() reorder clause list as little as possible

  2. Allow usage of match_orclause_to_indexcol() for joins

  3. Skip not SOAP-supported indexes while transforming an OR clause into SAOP

  4. Remove the wrong assertion from match_orclause_to_indexcol()

  5. Teach bitmap path generation about transforming OR-clauses to SAOP's

  6. Transform OR-clauses to SAOP's during index matching

  7. Fix the value of or_to_any_transform_limit in postgresql.conf.sample

  8. Transform OR clauses to ANY expression

  9. MergeAttributes code deduplication

  10. SEARCH and CYCLE clauses

  11. Improve estimation of OR clauses using extended statistics.

  12. Teach btree to handle ScalarArrayOpExpr quals natively.

  13. Revise collation derivation method and expression-tree representation.

  14. Instead of trying to force WHERE clauses into CNF or DNF normal form,

On Fri, Feb 16, 2024 at 1:32 PM Andrei Lepikhov
<a.lepikhov@postgrespro.ru> wrote:
>
> On 16/2/2024 07:00, jian he wrote:
> > On Wed, Feb 14, 2024 at 11:21 AM Andrei Lepikhov
> > <a.lepikhov@postgrespro.ru> wrote:
> > My OS: Ubuntu 22.04.3 LTS
> > I already set the max_parallel_workers_per_gather to 10.
> > So for all cases, it should use parallelism first?
> >
> > a better question would be:
> > how to make the number of OR less than 29 still faster when
> > enable_or_transformation is ON by only set parameters?
> In my test environment this example gives some subtle supremacy to ORs
> over ANY with only 3 ors and less.
> Please, provide next EXPLAIN ANALYZE results for the case you want to
> discuss here:
> 1. with enable_or_transformation enabled
> 2. with enable_or_transformation disabled
> 3. with enable_or_transformation disabled but with manual transformation
> OR -> ANY done, to check the overhead of this optimization.
>

you previously mentioned playing with parallel_tuple_cost and
parallel_setup_cost.
(https://www.postgresql.org/message-id/e3338e82-a28d-4631-9eec-b9c0984b32d5%40postgrespro.ru)

So I did by
`
SET parallel_setup_cost = 0;
SET parallel_tuple_cost = 0;
`

After setting these parameters, overall enable_or_transformation ON is
performance better.
sorry for the noise.
so now I didn't find any corner case where enable_or_transformation is
ON peforms worse than when it's OFF.

+typedef struct OrClauseGroupEntry
+{
+ OrClauseGroupKey key;
+
+ Node   *node;
+ List   *consts;
+ Oid scalar_type;
+ List   *exprs;
+} OrClauseGroupEntry;

I found that the field `scalar_type` was never used.