[GENERAL] adding columns with defaults is not implemented

[Marcelo]

Hello, Using Postgres 7.4, I am trying to perform an "alter table temptable add column "myCol" serial"   It gives the following msg ERROR:  adding columns with defaults is not implemented   You cannot add a column that is serial in a table which already has data in postgres 7.   Is there a way I can create a serial column on a table which already has data? Or is the only solution upgrading to postgres 8 ?   Thanks