Re: Postgres not using array - Mailing list pgsql-performance

From André Volpato
Subject Re: Postgres not using array
Date
Msg-id 48AD80FA.30100@ecomtecnologia.com.br
Whole thread Raw
In response to Re: Postgres not using array  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Postgres not using array  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Tom Lane escreveu:
> =?ISO-8859-1?Q?Andr=E9_Volpato?= <andre.volpato@ecomtecnologia.com.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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