It appears it scanes the type_idx once per opereator. IN gets broken
down into ORs
Is this what the TODO entry 'Make IN / NOT IN have similar performance
as EXISTS' means?
--
Rod
----- Original Message -----
From: "Oleg Bartunov" <oleg@sai.msu.su>
To: "Pgsql Hackers" <pgsql-hackers@postgresql.org>; "Tom Lane"
<tgl@sss.pgh.pa.us>
Sent: Monday, May 13, 2002 9:42 AM
Subject: [HACKERS] strange explain
> Hi,
>
>
> I've got performance problem and while I'dont ready to describe it
> I'd like to ask about strange explain:
>
> tour=# explain analyze select * from tours where
> ( operator_id in (2,3,4,5,7) and type_id = 2 ) or
> ( operator_id = 8 and type_id=4 );
>
> NOTICE: QUERY PLAN:
>
> Index Scan using type_idx, type_idx, type_idx, type_idx, type_idx,
type_idx on tours (cost=0.00..12.25 rows=1 width=1091) (actual
time=0.26..0.26 rows=0 loops=1)
> Total runtime: 0.45 msec
>
> EXPLAIN
>
> What does many 'type_idx' means ?
>
> Theare are 2 indices - operator_idx and type_idx.
>
>
> Regards,
> Oleg
> _____________________________________________________________
> Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
> Sternberg Astronomical Institute, Moscow University (Russia)
> Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
> phone: +007(095)939-16-83, +007(095)939-23-83
>
>
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