Fabien COELHO <[EMAIL PROTECTED]> writes: > The issue is that when one does (in pg 8.3.5) > ALTER TABLE foo ADD CONSTRAINT xxx UNIQUE ON (...); > this results in a constraint *and* an index, but when one does only the > corresponding: > CREATE UNIQUE INDEX foo(...); > then the index is created but there is no constraint.
This is intentional. You didn't create a constraint in the sense of the SQL standard, and furthermore it may very well be impossible to represent the index as a constraint in information_schema. (For instance, the index might be functional or partial --- in fact, it most likely is special in some way, or you'd not have bothered to use the nonstandard syntax to make it.) > Also, there is a minor bug in the documentation, which was the another > source of my troubles: > information_schema.KEY_COLUMN_USAGE.position_in_unique_constraint > is tagged as "NOT IMPLEMENTED", but it looks like it is implemented. Yeah, looks like the documentation is out of date there. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers