Hi All, my database server has very high load in this morning. I've found the problem. One of my index was not used so far! it's interesting:
addb=> \d banners Table "banners" Attribute | Type | Modifier ------------+--------------------------+---------------------------------------------------- b_no | integer | not null default nextval('banners_b_no_seq'::text) usr_no | integer | b_ext | character varying(10) | b_link | character varying(100) | b_from | date | b_to | date | b_lastview | timestamp with time zone | default now() b_maxview | integer | b_curview | integer | default 0 b_maxclick | integer | b_curclick | integer | default 0 b_weight | integer | default 1 b_curwg | double precision | default 0 b_active | boolean | default 'f'::bool last_upd | timestamp with time zone | default now() upd_usr | integer | b_name | character varying(40) | Indices: b_usr_no_idx, banners_b_no_key addb=> EXPLAIN SELECT b_link FROM banners WHERE b_no = 3; NOTICE: QUERY PLAN: Seq Scan on banners (cost=0.00..1.57 rows=1 width=12) EXPLAIN addb=> DROP INDEX banners_b_no_key; DROP addb=> CREATE INDEX banners_b_no_key ON banners (b_no); CREATE addb=> EXPLAIN SELECT b_link FROM banners WHERE b_no = 3; NOTICE: QUERY PLAN: Index Scan using banners_b_no_key on banners (cost=0.00..4.43 rows=1 width=12) EXPLAIN addb=> Why index wasn't used ? postgresql-7.1.2, redhat 7.0, kernel:2.2.19 Thanks, Gabor ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html