> Is there a better way? I think you could use a User Data Type. Then pass that as parameter to your aggregate function. That is: you would pass (4, 'meter') (400, 'mm') (100, 'cm') to your aggregate function. Each one is a user datatype: CREATE TYPE mytype AS ( v double precision, t varchar(10) ); See http://www.postgresql.org/docs/8.4/static/rowtypes.html This is the example based on a custom data type of complex numbers: http://www.postgresql.org/docs/8.4/static/xaggr.html -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general