Assuming you are joining on "Table 1".id = "Table 2".id - do you have indexes on both columns? Have you analyzed your tables + indexes (are there statistics available?) If not those criterias are met, it is unlikely that postgres will choose an index scan.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Fernando Lujan Sent: den 21 mars 2006 19:08 To: pgsql-performance@postgresql.org Subject: [PERFORM] Sequence Scan vs. Index scan Hi guys, I'm trying to figure out when Sequence Scan is better than Index Scan. I just want to know this because I disabled the sequence scan in postgresql and receive a better result. :) Two tables. Table 1 (1 million rows ) ----------- id text table2_id Table 2 (300 thousand rows) ---------- id text 2 When I join these two tables I have a sequence_scan. :( Thanks in advance. Fernando Lujan ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
