Re: Bugs in CREATE/DROP INDEX CONCURRENTLY

And here is a version for 9.1.  This omits the code changes directly
relevant to DROP INDEX CONCURRENTLY, but includes the changes to avoid
transactional updates of the pg_index row during CREATE CONCURRENTLY,
as well as the changes to prevent use of not-valid or not-ready indexes
in places where it matters.  I also chose to keep on using the
IndexIsValid and IndexIsReady macros, so as to avoid unnecessary
divergences of the branches.

I think this much of the patch needs to go into all supported branches.

            regards, tom lane