Re: database not using indexes, yet

2011/11/18 Silvio Brandani <silvio(dot)brandani(at)tech(dot)sdb(dot)it>

> On postgres 8.3.11 on linux centos 5 we have a table not too big with
> primary key index on
>
> Indexes:
> "aida_references_pkey" PRIMARY KEY, btree (aida_reference_id)
>
> the query not use index:
>
> aidadb=# explain analyze select aida_reference_id from
> aida.aida_references where aida_reference_id = '3145';
> QUERY PLAN
> ------------------------------**------------------------------**
> ------------------------------**----------------------
> Seq Scan on aida_references (cost=0.00..51489.15 rows=1 width=4) (actual
> time=0.173..1457.643 rows=1 loops=1)
> Filter: (aida_reference_id = 3145)
> Total runtime: 1457.696 ms
>
>
> already executed the vacuum ,reindex.
>
> Please help
>
> --
> Silvio Brandani
>
>
>
Hi Silvio,
how many rows do you have in the table?
Usually PostgreSQL doesn't want to use index when the table is small.

regards
Szymon

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