On 08/24/11 9:18 AM, Carlos Henrique Reimer wrote:
I need to improve performance for a particular SQL command but facing difficulties to understand the explain results.
you're joining like 50 tables in nested selects, getting 200 rows, and its only taking 3.5 seconds? where's the problem?
you can paste EXPLAIN output into http://explain.depesz.com and get output like http://explain.depesz.com/s/hfWp which helps format it for better understanding.
in this case, most of the time (3.35s worth) appears to be spent on sorts and an nidex scan inside an inner merge join thats processing 77000 rows.
-- john r pierce N 37, W 122 santa cruz ca mid-left coast -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
