Tom Lane napsal(a):
> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
>> In fact, I don't think there's any low-level data format changes yet
>> between 8.3 and 8.4, so this would be a comparatively easy release to
>> implement upgrade-in-place. There's just the catalog changes, but AFAICS
>> nothing that would require scanning through relations.
>
> After a quick scan of the catversion.h changelog (which hopefully covers
> any such changes): we changed sequences incompatibly, we changed hash
> indexes incompatibly (even without the pending patch that would change
> their contents beyond recognition), and Teodor did some stuff to GIN
> indexes that might or might not represent an on-disk format change,
> you'd have to ask him. We also whacked around the sort order of
> bpchar_pattern_ops btree indexes.
Hmm, It seems that reindex is only good answer on all these changes. Sequence
should be converted during catalog conversion.
Another idea is to create backward compatible AM and put them into separate
library. If these AM will work also with old page structure then there should
not be reason for reindexing or index page conversion after upgrade.
Zdenek
--
Zdenek Kotala Sun Microsystems
Prague, Czech Republic http://sun.com/postgresql