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

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

-------------------------------------------------------

--
Ing. Yasset Pérez Riverol.
Grupo de Bioinformática.
CIGB, La Habana, Cuba.

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"La alegría está en la lucha, en el esfuerzo,
en el sufrimiento que supone la lucha y no
en la victoria."
Mahatma Gandhi