Re: [HACKERS] Duplicate usage of tablespace location?

Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> writes:
> I noticed by the following report, PostgreSQL can share the same
> directory as tablespaces of two servers with different
> pg-versions.

> https://www.postgresql.org/message-id/2008148.rxBNyNRHPZ@peanuts2

> 8.4 checked that the tablespace location is empty, but from 9.0,
> the check is replaced with creating a PG_PGVER_CATVER
> subdirectory. This works for multiple servers with the same
> version, but don't for servers with different versions.

Please explain why you think it doesn't work.  This patch seems to
be reverting an intentional behavioral change, and you haven't
really explained why we'd want to.  It certainly doesn't look like
it addresses the referenced complaint about pg_basebackup behavior.
        regards, tom lane