On Mon, May 23, 2011 at 1:53 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Maybe. But casts would be the least of our concerns if we were trying
> to change the column type. Changing typmod doesn't affect the set of
> operations that could be applied to a column, whereas changing type
> surely does.
OK, this is the crucial point I was missing. Sorry for being a bit
fuzzy-headed about this.
My mental model of our type system, or of what a type system ought to
do, just doesn't match the type system we've got.
So let's do it the way you proposed.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company