Re: Prototype: In-place upgrade v02

Heikki Linnakangas napsal(a):
> Zdenek Kotala wrote:
>> 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. 
> 
> Isn't that exactly what we want to avoid with upgrade-in-place? As long 
> as the conversion can be done page-at-a-time, without consulting other 
> pages, we can do it when the page is read in.

Yes, but I meant what we can do for 8.4.
    Zdenek