Re: [GENERAL] Which is faster: md5() or hashtext()?
On Fri, November 5, 2010 09:52, Grzegorz JaÅkiewicz wrote: > Timing is on. > I would say hashtext is consequently beating md5 in terms of performance > here. nice concise answer, thanks Grzegorz. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Which is faster: md5() or hashtext()?
Timing is on. psql (9.1devel) Type "help" for help. # select count(hashtext(a::text)) FROM generate_series(1,1) a; count --- 1 (1 row) Time: 106.637 ms # select count(hashtext(a::text)) FROM generate_series(1,100) a; count - 100 (1 row) Time: 770.823 ms # select count(md5(a::text)) FROM generate_series(1,100) a; count - 100 (1 row) Time: 1238.453 ms # select count(hashtext(a::text)) FROM generate_series(1,100) a; count - 100 (1 row) Time: 763.169 ms # select count(md5(a::text)) FROM generate_series(1,100) a; count - 100 (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@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
[GENERAL] Which is faster: md5() or hashtext()?
G'day, I need to do a mass update on about 550 million rows (I will be breaking it up into chunks based on id value so I can monitor progress). Hashing one of the columns is part of the process and I was wondering which is more efficient/faster: md5() or hashtext()? hashtext() produces a nice tight integer value, whereas md5() produces a fixed string. My instinct says hashtext(), but there may be a lot more to hashext() than meets the eye. Any ideas? Thanks Henry -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general