Horton

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

Teodor Sigaev <teodor@sigaev.ru>

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From: Teodor Sigaev <teodor@sigaev.ru>
To: Feng Tian <ftian@vitessedata.com>
Cc: Pgsql Hackers <pgsql-hackers@postgresql.org>
Date: 2015-12-26T19:25:19Z
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,

> This is great.   I got a question, is it possible make btree index to support OR
> as well?  Is btree supports more invasive, in the sense that we need to do
> enhance ScanKey to supports an array of values?
Btree now works by follow: find the max/min tuple which satisfies condtions and 
then executes forward/backward scan over leaf pages. For complicated clauses 
it's not obvious how to find min/max tuple. Scanning whole index isn't an option 
from preformance point of view.

-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
                                                    WWW: http://www.sigaev.ru/