Concurrency question

Any help here appreciated.

I ran a vacuum verbose analyze on a database over the weekend. It ran fine
until it tried to vacuum a table less than 2000 pages. It successfully
acquired a ShareUpdateExclusiveLock as I would expect.
There was an idle thread that had an AccessSharelock on the same table.
Compatible locks I would think. But the vacuum hung until the
AccessSharelock thread was cancelled - 11 hours in all.
This table normally vacuums in less than 15 seconds. This AccessSharelock
came from a query that formerly was part of a transaction sent from a remote
server. Could it be that it hung because it was
A transaction? Even so I thought those lock types were compatible.

As always thanks for your time.

Mark Steben│Database Administrator│
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