Help with query. (*) - Mailing list pgsql-sql

From Diehl, Jeffrey
Subject Help with query. (*)
Date
Msg-id B51F0C636E578A4E832D3958690CD73E0130BD9A@es04snlnt
Whole thread Raw
Responses Re: [GENERAL] Help with query. (*)
List pgsql-sql
I'm having difficulty writing a query which I really can't live without...

I need to get a list of records from table A for which there are
corresponding records in table B.  I've tried to use the intersect clause,
but it doesn't seem to work, or it runs far too long.  For example:

select * from A
    where 1=1
    intersect select * from A where
    B.x=A.x
    and A.y=B.y
    and A.z=B.z
    limit 100

I need the most efficient method possible; my A tables have upward of 5
Million records.  The B table, btw, only has about 100 records.


Any help will be most appreciated.


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