On 08/22/2012 12:27 PM, Wells Oliver wrote:
We have a lot of tables which store numeric data. These tables all use the numeric type, where the values are 95% integer values. We used numeric because it eliminated the need for casting during division to yield a floating point value. I'm curious as to whether this would have performance and/or disk size implications.
Yes, and yes, though the gap seems to have shrunk a lot since I first started using Pg.
It's easy to concoct fairly meaningless micro-benchmarks, but you should really try it with some real queries you run on your real schema. Take a copy of your data, convert it, and run some tests. Use `pg_total_relation_size` to compare the numeric and int versions of the relations after `CLUSTER`ing them to debloat and reindex them.
Would converting these columns to integer (or double precision on the handful that require the precision) and forcing developers to use explicit casting be worth the time?
Without knowing your workload and your constraints, that's a "how blue is the sky" question.
-- Craig Ringer -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
