Thanks David
In any case the cost-based stuff throttles I/O only (per the docs at
least) but even while sleeping it still holds its lock. And it won't
be kicked off of the lock by other processes. I don't see where it is
documented that the autovacuum cost settings are altered during the
anti-wraparound vacuum so I presume it will still sleep by default.
I knew I was misunderstanding something. I had picked up the impression
that the vacuum process cost_delay released the lock for the period. Not
just do nothing. Seems like that would be worth mentioning in the Docs.
I'm learning this from the inside out in the tradition of "well someone
has to do it". I'm sure I'm not alone.
-Senor
