Обсуждение: dropping constraints

Hi All;

we have a few not null constraints we want to drop on very large tables.
Unfortunately the drop's are taking hours. Is there a way to drop a not null
constraint via the system catalogs?

Thanks in advance

Kevin Kempter <cs_dba@consistentstate.com> writes:
> we have a few not null constraints we want to drop on very large tables.
> Unfortunately the drop's are taking hours. Is there a way to drop a not null
> constraint via the system catalogs?

Dropping a NOT NULL constraint is a trivial operation.  The problem is
probably that you are blocked waiting to get a lock on the table.
Look for idle-in-transaction sessions that are holding locks on the
target table.

            regards, tom lane

]
> Kevin Kempter <cs_dba@consistentstate.com> writes:
> > we have a few not null constraints we want to drop on very large tables.
> > Unfortunately the drop's are taking hours. Is there a way to drop a not
> > null constraint via the system catalogs?
>
> Dropping a NOT NULL constraint is a trivial operation.  The problem is
> probably that you are blocked waiting to get a lock on the table.
> Look for idle-in-transaction sessions that are holding locks on the
> target table.
>
>             regards, tom lane

thanks