Re: BUG #6712: PostgreSQL 9.2 beta2: alter table drop constraint does not work on inherited master table

> From: pgsql-bugs-owner(at)postgresql(dot)org [mailto:pgsql-bugs-owner(at)postgresql(dot)org] On Behalf Of miroslav(dot)sulc(at)fordfrog(dot)com
> Sent: Saturday, June 30, 2012 4:28 PM
> The following bug has been logged on the website:

> Bug reference: 6712
> Logged by: Miroslav Šulc
> Email address: miroslav(dot)sulc(at)fordfrog(dot)com
> PostgreSQL version: Unsupported/Unknown
> Operating system: Gentoo Linux
> Description:

> here is the test case:

> test=# create table test_constraints (id int, val1 varchar, val2 int, unique
> (val1, val2));
> NOTICE: CREATE TABLE / UNIQUE will create implicit index
> "test_constraints_val1_val2_key" for table "test_constraints"
> CREATE TABLE
> test=# create table test_constraints_inh () inherits (test_constraints);
> CREATE TABLE
> test=# alter table only test_constraints drop constraint
> test_constraints_val1_val2_key;
> ERROR: constraint "test_constraints_val1_val2_key" of relation
> "test_constraints_inh" does not exist

> postgresql tries to drop the constraint even from descendant table though
> "only" is specified.

In function ATExecDropConstraint(), for the constarint "test_constraints_val1_val2_key" con->connoinherit is false,
due to which it tries to drop the constrint from child table as well.
I have checked that from function index_constraint_create() when it calls function CreateConstraintEntry(), the flag for noinherit passed is false.
I think this is the reason of failure for the same.

With Regards,
Amit Kapila.