Gaetano Mendola wrote: > Hi, > I was wondering if there is a clean view to lock the usage of a view. > > Basically during a schema migration, with applications still running a > typical > schema change is: > > BEGIN; > ALTER TABLE x ADD COLUMN (a INTEGER); > CREATE OR REPLACE VIEW v_x > AS > SELECT a,b FROM x; > COMMIT; > > now the issue is that if an application performs a: > > SELECT * from v_x; > > between the ALTER and the view redefinition then a deadlock happens. > > I'm preventing this issue doing a: > > ALTER VIEW v_x ALTER COLUMN b DROP DEFAULT; > (anyway there was no default on the view) > before the ALTER TABLE, that's basically reorders the locks sequence > avoiding the dead lock.
So what you want is LOCK VIEW f;
Exactly that, it would be ideal indeed that was exactly my first attempt.
