Re: Prototype: In-place upgrade v02

Heikki Linnakangas napsal(a):
> Zdenek Kotala wrote:
>> Heikki Linnakangas napsal(a):
>>> Relation forks didn't change anything inside relation files, so no 
>>> scanning of relations is required because of that. Neither will the 
>>> FSM rewrite. Not sure about DSM yet.
>>
>> Does it mean, that if you "inject" old data file after catalog 
>> upgrade, then FSM will works without any problem?
> 
> Yes. You'll need to construct an FSM, but it doesn't necessarily need to 
> reflect the reality. You could just fill it with zeros, meaning that 
> there's no free space anywhere, and let the next vacuum fill it with 
> real information. Or you could read the old pg_fsm.cache file and fill 
> the new FSM accordingly.

I think zeroed FSM is good, because new items should not be added on to old page.
    Zdenek


-- 
Zdenek Kotala              Sun Microsystems
Prague, Czech Republic     http://sun.com/postgresql