Re: Postgres not using array

From: André Volpato <andre(dot)volpato(at)ecomtecnologia(dot)com(dot)br>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Postgres not using array
Date: 2008-08-21 14:51:38
Message-ID: 48AD80FA.30100@ecomtecnologia.com.br
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Tom Lane escreveu:
> =?ISO-8859-1?Q?Andr=E9_Volpato?= <andre(dot)volpato(at)ecomtecnologia(dot)com(dot)br> writes:
>
>> Explain output:
>> HashAggregate (cost=19826.23..19826.96 rows=73 width=160) (actual
>> time=11826.754..11826.754 rows=0 loops=1)
>> -> Subquery Scan b2 (cost=19167.71..19817.21 rows=722 width=160)
>> (actual time=11826.752..11826.752 rows=0 loops=1)
>> Filter: (bds_internacoes(200805, 200806, (b2.cod)::text,
>> 'qtdI'::text, 'P'::bpchar) >= 1::numeric)
>> -> Limit (cost=19167.71..19248.89 rows=2165 width=48) (actual
>> time=415.157..621.043 rows=28923 loops=1)
>>
>
> So I guess the question is "what is the bds_internacoes function, and
> why is it so slow?"

This function is quite fast:
Aggregate (cost=5.17..5.18 rows=1 width=12) (actual time=0.286..0.287
rows=1 loops=1)
-> Index Scan using iinternacoes4 on internacoes (cost=0.01..5.16
rows=1 width=12) (actual time=0.273..0.273 rows=0 loops=1)
Index Cond: ((((ano * 100) + mes) >= 200801) AND (((ano * 100)
+ mes) <= 200806) AND ((cod_benef)::text = '0005375200'::text))
Filter: (tipo_internacao = 'P'::bpchar)
Total runtime: 0.343 ms

The problem is that its fired up against 29K rows, wich takes the
total runtime about 10s.

We are guessing that a dual core 3.0GHz will beat up a quad core 2.2,
at least in this environmnent with less than 4 concurrent queryes.

--

[]´s, ACV

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