Re: Swapping volumes under tablespaces: supported?

Kenneth Tilton <ktilton(at)mcna(dot)net> writes:
> Currently we refresh our test DB instance by cloning the single production
> EC2 volume we use for our entire PG environment and attaching it to the dev
> EC2 instance running Postgres. This works well.

> But now we are about to add a large quantity of largely static data to our
> database. To avoid cloning the static data every time we refresh test
> (several times a day), we want to put the new data in its own tablespace
> pointing to a different volume, then clone only the default volume to which
> the Postgres and default spaces point.

> Is that supported?

No. XID and table-OID considerations are going to give you headaches.

It's possible you can make it work as long as the static data is really
static (not "largely" static, but absolutely read-only) and you VACUUM
FREEZE all of it and then don't change the catalog entries about it in
the DB image being cloned. But you shouldn't imagine that we consider
this supported. If it breaks you get to keep both pieces.

regards, tom lane