cf3e298512
This commit reverts the work done by commits 3ba59ccc89 and 72e78d831a. Those commits were incorrect in asserting that we never acquire any other heavy-weight lock after acquring page lock other than relation extension lock. We can acquire a lock on catalogs while doing catalog look up after acquring page lock. This won't impact any existing feature but we need to think some other way to achieve this before parallelizing other write operations or even improving the parallelism in vacuum (like allowing multiple workers for an index). Reported-by: Jaime Casanova Author: Amit Kapila Backpatch-through: 13 Discussion: https://postgr.es/m/CAJKUy5jffnRKNvRHKQ0LynRb0RJC-o4P8Ku3x9vGAVLwDBWumQ@mail.gmail.com