Philip Warner <pjw(at)rhyme(dot)com(dot)au> writes:
> Does this mean that ANALYZE will take an exclusive lock on pg_listener
> until the ANALYZE finishes? Or is there some other cause?
ANALYZE does not take an exclusive lock on anything. However, the
async.c functions want AccessExclusiveLock on pg_listener, so they
quite possibly would get blocked by ANALYZE's not-so-exclusive lock.
Possibly we could reduce the strength of the lock taken by the async.c
functions ... I haven't thought hard about it. The long-term answer is
certainly a wholesale rewrite of the listen/notify mechanism.
regards, tom lane