Re: Information Schema and constraint names not unique

Tom Lane wrote:
> Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> writes:
> > On Thu, Nov 06, 2003 at 11:42:13AM -0500, Tom Lane wrote:
> >> I don't have a problem with switching from "$1" to "tablename_$1", or
> >> some such, for auto-generated constraint names. But if it's not
> >> guaranteed unique, does it really satisfy Philip's concern?
>
> > It certainly _is_ unique within a schema ...
> > (But what happens to the constraint name when the table is renamed?)
>
> Exactly. Also consider manually-assigned constraint names that happen
> to look like "foo_$n" --- these could cause trouble if table foo is
> created later. To make a guarantee of uniqueness would require more
> infrastructure than just a simple hack of the constraint name generator
> logic.
>
> BTW we also have some problems with auto-generated names for column
> constraints; these generally look like "tablename_columnname", and
> that's not unique:
>
> regression=# create table foo (f1 int check (f1 > 0) check (f1 < 10));
> ERROR: check constraint "foo_f1" already exists

Is this a TODO to fix?

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