pg_upgrade and visibility map files

I have found an odd mistake in pg_upgrade 9.2, though I don't think it
is a problem. Specifically, pg_upgrade will copy a visibility map (vm)
>1GB extent file from the old cluster to the new, even if the
crash-safety of the old vm file does not match the new server. For
example, 19323_vm would not be copied, but 19323_vm.1 would be.

I don't think this is a problem because having a >1GB vm file would
require the table to be 64TB (1GB * 8 * 8k), and our max table size is
32TB. I am not planning to fix this in 9.2; this code is restructured
in git head and does not have this problem.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +