Re: Esta es la estrucutra de las tablas.....

2008/1/28, Yasset Perez Riverol <yasset(dot)perez(at)biocomp(dot)cigb(dot)edu(dot)cu>:
>
> Despues del VACUMM:
>
> EXPLAIN select tabla1.id, tabla2.id from tabla1 INNER JOIN tabla3 ON
> (tabla3.id_tabla1 = tabla1.id) INNER JOIN tabla2 ON (tabla2.id =
> tabla3.id_tabla2);
> QUERY PLAN
>
> --------------------------------------------------------------------------------
> Hash Join (cost=313052.04..757887.84 rows=2134672 width=96)
> Hash Cond: ((tabla3.id_tabla1)::text = (tabla1.id)::text)
> -> Hash Join (cost=1.99..289972.69 rows=2134672 width=96)
> Hash Cond: ((tabla3.id_tabla2)::text = (tabla2.id)::text)
> -> Seq Scan on tabla3 (cost=0.00..232237.53 rows=9703053
> width=96)
> -> Hash (cost=1.44..1.44 rows=44 width=48)
> -> Seq Scan on tabla2 (cost=0.00..1.44 rows=44 width=48)
> -> Hash (cost=195175.69..195175.69 rows=5412669 width=48)
> -> Seq Scan on tabla1 (cost=0.00..195175.69 rows=5412669
> width=48)
> (9 rows)
>
> La estructura de las tablas son las siguientes:
>
>
> \d tabla3
>
> Table "public.tabla3"
> Column | Type | Modifiers
> --------------+------------------------+-----------
> id_tabla2 | character varying(15) |
> id_tabla1 | character varying(15) |
> other_field | character varying(300) |
> id_tabla4 | integer |
>
> Foreign-key constraints:
> "tabla3_id_tabla1_fkey" FOREIGN KEY (id_tabla1) REFERENCES tabla1(id)
> ON
> UPDATE CASCADE ON DELETE CASCADE
> "tabla3_id_tabla4_fkey" FOREIGN KEY (id_tabla4) REFERENCES
> mol_tabla4(id)
> ON UPDATE CASCADE ON DELETE CASCADE
> "tabla3_id_tabla2_fkey" FOREIGN KEY (id_tabla2) REFERENCES tabla2(id)
> ON
> UPDATE CASCADE ON DELETE CASCADE
>
>
>
> \d tabla1
> Table "public.tabla1"
> Column | Type | Modifiers
> -------------+------------------------+-----------
> id | character varying(15) | not null
> id_2 | character varying(12) |
> format | character varying(300) |
> porperty3 | character varying(100) |
> Indexes:
> "tabla1_pkey" PRIMARY KEY, btree (id)
> "tabla1_unique" UNIQUE, btree (id_2, format)
>
> \d tabla2
> Table "public.tabla2"
> Column | Type | Modifiers
> -------------+------------------------+-----------
> id | character varying(15) | not null
> name | character varying(100) |
> description | text |
> website | character varying(100) |
> email | character varying(100) |
> Indexes:
> "tabla2_pkey" PRIMARY KEY, btree (id)
>
>
> Alguna idea de como bajar este tiempo. (Maquina Dual AMD Athlon 2.4, 2 GB
> de
> RAM)
>
>
> Sldos Yasset

Agregale un índice en la tabla3 por el campo id_tabla1. Hacé Vacuum y mostrá
el explain nuevamente.
Silvio

--
Silvio Quadri