Hello I rechecked Depesz's article - http://www.depesz.com/2011/07/01/waiting-for-9-2-not-valid-checks/
The behave of current HEAD is different than behave described in article. "alter table a validate constraint a_a_check" needs a access exclusive locks and blocks table modification - I tested inserts. Is it expected behave. session one: postgres=# create table a(a int); CREATE TABLE postgres=# alter table a add check (a > 0) not valid; ALTER TABLE postgres=# begin; BEGIN postgres=# alter table a validate constraint a_a_check; ALTER TABLE session two: postgres=# update a set a = 100; -- it waits to commit in session one Regards Pavel Stehule -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
