Re: Two indexes on same column

Hi, I was reading about indexes and I have a question:

is possible to use "hash" like index method in primary key constraints??

thanks

2011/7/20 Raghavendra <raghavendra(dot)rao(at)enterprisedb(dot)com>:
>
> On Wed, Jul 20, 2011 at 2:39 PM, Vlastimil Krejcir <krejcir(at)ics(dot)muni(dot)cz>
> wrote:
>>
>>  Hi,
>>
>>  what index is used (and according to what rules) when there are two (or
>> more) different indexes defined on one column? Assume:
>>
>> CREATE TABLE example (
>> id SERIAL PRIMARY KEY,
>> ...);
>> CREATE INDEX example_id_idx ON example USING hash (id);
>>
>> By default there are btree index created and the hash index is then
>> created. So there are two indexes on column "id". Are there described
>> somewhere what index is used and when? Does it depend on query analyzer and
>> planner?
>>
>> Thanks
>>
>
> You are right, depends on the optimizer and query to which index to choose.
> EXPLAIN command on the query will give you the optimizer path.
>
> ---
> Regards,
> Raghavendra
> EnterpriseDB Corporation
> Blog: http://raghavt.blogspot.com/
>
>

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