On Jun 15, 2010, at 9:31 , Heikki Linnakangas wrote:
> You could avoid changing the meaning of fn_expr by putting the check in the parse analysis phase, into
transformFuncCall().That would feel safer at least for back-branches.
For 9.0, wouldn't a cleaner way to accomplish this be a seperate type for expressions, say pg_expr, instead of storing
themas text? With an input function that unconditionally raises and error and no cast to pg_expr, creating new
instancesof that type would be impossible for normal users. The output function and casts to text would call
pg_get_expr()with zero as the second argument.
The internal representation wouldn't change, it's just the type's OID in the catalog that'd be different.
best regards,
Florian Pflug