Re: Two indexes on same column
От | Ernesto Quiñones |
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Тема | Re: Two indexes on same column |
Дата | |
Msg-id | CAMB2kH60A5Gf_63jDi7d2hq1e2hiPgNMKt6frvp+TL_Te2Uysg@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Two indexes on same column (Raghavendra <raghavendra.rao@enterprisedb.com>) |
Список | pgsql-general |
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.rao@enterprisedb.com>: > > On Wed, Jul 20, 2011 at 2:39 PM, Vlastimil Krejcir <krejcir@ics.muni.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/ > > -- ---------------------------------------------------------- Visita : http://www.eqsoft.net ---------------------------------------------------------- Sigueme en Twitter : http://www.twitter.com/ernestoq
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