"Albe Laurenz" <laurenz.albe@wien.gv.at> writes:
> roopasatish wrote:
>> I have an issue with the add foreign key constraint which
>> goes for waiting and locks other queries as well.
>>
>> ALTER TABLE ONLY holding_positions ADD CONSTRAINT
>> holding_positions_stock_id_fkey FOREIGN KEY (stock_id)
>> REFERENCES stocks (stock_id) MATCH SIMPLE
>> ON UPDATE NO ACTION ON DELETE NO ACTION;
>>
>> The holding_positions table has no data in it as yet.
> Look in pg_catalog.pg_locks for a second transaction that
> holds a lock on the table holding_positions.
This statement also needs to get lock on the referenced table "stocks".
An open transaction that's referenced either table will block it.
regards, tom lane