Re: Moving tablespaces

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Magnus Hagander <magnus@hagander.net>
Cc: Bruce Momjian <bruce@momjian.us>, PostgreSQL-documentation <pgsql-docs@postgresql.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2011-12-04T16:41:30Z
Lists: pgsql-hackers
Magnus Hagander <magnus@hagander.net> writes:
> And IIRC, we don't actually *use* spclocation anywhere.

Just for pg_dump, I think.

> How about we
> just get rid of them as independents? We could either:

> 1) Remove the column. Rely on the symlink. Create a
> pg_get_tablespace_location(oid) function, that could be used by
> pg_dumpall and friends, that just reads the symlink.

Hm, how portable is symlink-reading?  If we can actually do that
without big headaches, then +1.

> 2) Forcibly update the spclocation column when we start the server to
> be whatever the symlink points to. That will at least automatically
> restore the system to being consistent.

-1, running a transaction at that level will be a giant pita.
And how would you do it at all on a hot standby slave?

			regards, tom lane