Re: CIDR index use for '<<' operator
От | Bruce Momjian |
---|---|
Тема | Re: CIDR index use for '<<' operator |
Дата | |
Msg-id | 200010090738.DAA05696@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: CIDR index use for '<<' operator (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-general |
Added to TODO. > "Kendall Koning" <kkoning@egl.net> writes: > > Postgres doesn't seem to make use of indexes when doing operations with the > > CIDR '<<' (contains) operator. > > You're right --- the system has no idea that the '<<' operator has any > relationship to the sort ordering of CIDR indexes. > > Seems like it'd be possible to improve this along the same lines that > we use to make LIKE and regexp matches indexable: derive lower and > upper bounds on the CIDR variable from a 'cidr-var << cidr-constant' > clause, and use those to create 'cidr-var >= lower-bound AND > cidr-var <= upper-bound' indexscan limit clauses. > > If you feel like tackling this, the "special index operator" support > in src/backend/optimizer/path/indxpath.c is the stuff that'd need to > be extended. > > regards, tom lane > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
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