On Wed, Dec 2, 2009 at 11:26 AM, Dimitri Fontaine <dfonta...@hi-media.com> wrote: > We already have had demand for read only tables (some on-disk format > optimisation would then be possible). What about having page level > read-only restriction, thus allowing the newer server version to operate > in read-only mode on the older server version pages, and convert on > write by allocating whole new page(s)?
I'm a bit confused. Read-only tables are tables that the user has said they don't intend to modify. We can throw an error if they try. What you're proposing are pages that the system treats as read-only but what do you propose to do if the user actually does try to update or delete (or lock) a record in those pages? If we want to avoid converting them to new pages we need to be able to at least store an xmax and set the ctid on those tuples. And probably we would need to do other things like set hint bits or set fields in the page header. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
