Re: Use of Functional Indexs and Planner estimates - Mailing list pgsql-performance

From Tom Lane
Subject Re: Use of Functional Indexs and Planner estimates
Date
Msg-id 1315.1086705210@sss.pgh.pa.us
Whole thread Raw
In response to Re: Use of Functional Indexs and Planner estimates  (Manfred Koizar <mkoi-pg@aon.at>)
List pgsql-performance
Manfred Koizar <mkoi-pg@aon.at> writes:
> So statistics gathering for expressional indexes will be in 7.5, but I
> don't know about the state of the planner ...

Planner support is there too:

2004-02-16 19:52  tgl

    * src/: backend/optimizer/path/costsize.c,
    backend/optimizer/util/relnode.c, backend/utils/adt/selfuncs.c,
    include/optimizer/pathnode.h, include/utils/selfuncs.h: Make use of
    statistics on index expressions.  There are still some corner cases
    that could stand improvement, but it does all the basic stuff.    A
    byproduct is that the selectivity routines are no longer
    constrained to working on simple Vars; we might in future be able
    to improve the behavior for subexpressions that don't match
    indexes.

I don't recall anymore what "corner cases" I had in mind for future
improvement.

            regards, tom lane

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