Re: CIDR index use for '<<' operator - Mailing list pgsql-general

From Bruce Momjian
Subject Re: CIDR index use for '<<' operator
Date
Msg-id 200010090738.DAA05696@candle.pha.pa.us
Whole thread Raw
In response to Re: CIDR index use for '<<' operator  (Tom Lane <tgl@sss.pgh.pa.us>)
List 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
>


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