Hellen Jiang <hjiang(at)federatedwireless(dot)com> writes:
> But from time and time, we found that it took forever to refresh materialized view( normally or concurrently), and there is no response to query from this materialized view.
That sounds like a locking problem. Have you looked into pg_locks
while this is happening, to see what may be waiting on what?
regards, tom lane