"Enke, Michael" <michael.enke@wincor-nixdorf.com> writes:
> But the description says: vacuum can run parallel to selects.
> This is than not true.
Sure it can; but that doesn't mean there is no interlocking at all.
The issue you have is not so much that the select is running as that it
is *not* running, ie, it's stopped on a particular page. As soon as it
moves off the modified page, the vacuum will be able to make progress.
regards, tom lane