Bruce Momjian napsal(a):
Zdenek Kotala wrote:
Tom Lane napsal(a):
Zdenek Kotala <[EMAIL PROTECTED]> writes:
Heikki Linnakangas napsal(a):
Perhaps we should just add the new attid attribute to the toast table,
but mark it as nullable?
Hmm, It seems to me as a good idea.
No, it's a really horrid idea. Nullable attributes complicate the C
code, and what in the world are we buying with it anyway? Just decide
what the field should contain and put it in there.
The problem what we try to solve is to perform this change during upgrade from
8.3->8.4. Extra value is a problem because it requires extra space and there is
not free space. It is temporal solution(hack) for 8.3->8.4.
Once we have the 'require free space' capability in a major Postgres
release, can't we use that to make space for the new TOAST field we will
need?
The problem is between 8.3 and 8.4. Unfortunately 8.3 does not have this
capability. And if it will be backported then space reservation on toast table
will be too expensive - you need to move one tuple which usually has BLCKSZ/4).
Zdenek
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
