Re: select count(*) from anIntColumn where int_value = 0; is very slow

>
> Hi
>
> we have a table with about 4 million rows. One column has an int value,
> there is a btree index on it. We tried to execute the following
> statement and it is very slow on a dual G5 2GHZ with 4 GB of RAM.
>
> explain analyze select count(*) from job_property where int_value = 0;
>
> Aggregate (cost=144348.80..144348.80 rows=1 width=0) (actual
> time=13536.852..13536.852 rows=1 loops=1)
> -> Seq Scan on job_property (cost=0.00..144255.15 rows=37459
> width=0) (actual time=19.422..13511.653 rows=42115 loops=1)
> Filter: (int_value = 0)
> Total runtime: 13560.862 ms

Is your int_value data type int4? If not then use "... from job_property
where int_value = '0'"
Indexes are used only if datatypes matches.

Rigmor Ukuhe

>
>
>
> Is this more or less normal or can we optimize this a little bit?
> FrontBase (which we compare currently) takes 2 seconds first time and
> about 0.2 seconds on second+ queries.
>
> regards David
>
>
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