Re: Improving performance on multicolumn query - Mailing list pgsql-performance

From Christopher Kings-Lynne
Subject Re: Improving performance on multicolumn query
Date
Msg-id 4371F765.1050209@familyhealth.com.au
Whole thread Raw
In response to Improving performance on multicolumn query  (Jan Kesten <jan.kesten@web.de>)
List pgsql-performance
> transfer=> explain analyse SELECT * FROM test WHERE test_a=9091150001
> AND test_b=1 AND test_c=2 AND test_d=0 AND test_e=0;
>
>  Index Scan using test_idx on test  (cost=0.00..50.27 rows=1 width=1891)
> (actual time=0.161..0.167 rows=1 loops=1)
>    Index Cond: (test_a = 9091150001::bigint)
>    Filter: ((test_b = 1) AND (test_c = 2) AND (test_d = 0) AND (test_e 0))
>
> So, what to do to speed things up? If I understand correctly this
> output, the planner uses my index (test_idx is the same as test_pkey
> created along with the table), but only for the first column.

Hi Jan,

If you're using 7.4.x then the planner can't use the index for unquoted
bigints.  Try this:

SELECT * FROM test WHERE test_a='9091150001' AND test_b='1' AND
test_c=''2 AND test_d='0' AND test_e='0';

Chris

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