Timing is on. psql (9.1devel) Type "help" for help. # select count(hashtext(a::text)) FROM generate_series(1,10000) a; count ------- 10000 (1 row) Time: 106.637 ms # select count(hashtext(a::text)) FROM generate_series(1,1000000) a; count --------- 1000000 (1 row) Time: 770.823 ms # select count(md5(a::text)) FROM generate_series(1,1000000) a; count --------- 1000000 (1 row) Time: 1238.453 ms # select count(hashtext(a::text)) FROM generate_series(1,1000000) a; count --------- 1000000 (1 row) Time: 763.169 ms # select count(md5(a::text)) FROM generate_series(1,1000000) a; count --------- 1000000 (1 row) Time: 1258.958 ms I would say hashtext is consequently beating md5 in terms of performance here. Just remember, that it returns integer, unlike md5 that returns text. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
