On Wed, Dec 05, 2007 at 11:43:08AM +0000,
Steve Grey <stevegrey78@gmail.com> wrote
a message of 153 lines which said:
> First work out the maximum number of times each value of X will occur in the
> table
A better solution, when you do not know this maximum number, is CREATE
AGGREGATE (http://www.postgresql.org/docs/8.1/interactive/xaggr.html)
See details :
http://www.bortzmeyer.org/agregats-postgresql.html
(Yes, it is in french but the SQL examples are in english, variable
names included, so they still can be useful for the OP).