Re: pg_upgrade project status

Zdenek Kotala wrote:
> Robert Haas píše v út 27. 01. 2009 v 09:45 -0500:
> 
>>> 1) Space reservation
>>> http://archives.postgresql.org/pgsql-hackers/2008-12/msg00886.php
>>> http://archives.postgresql.org/pgsql-hackers/2009-01/msg02031.php
>>>
>>> This patch is mandatory for page online conversion and MUST TO be part
>>> of postgreSQL 8.4. if not ... then we will be at the beginning next
>>> year.
>>>
>>> I sent updated version today.
>> I thought we pretty much had agreement that space reservation was not
>> a good solution to anything, although I admit I'm not quite clear on
>> what alternative was being proposed.
> 
> Maybe I miss something, but space reservation was selected as a best
> way. Please, Could you point me related mailing thread? 

Space reservation is the way to go, but I remain of the opinion that 
trying to predict the future is futile. When we know what we need (= 
around the beginning of 8.5 beta), we can backpatch a patch to reserve 
the needed amount of space on pages. It has to be dead simple to 
consider applying it to a stable branch, but something like "reserve X 
bytes for heap pages and Y bytes for b-tree pages if pre_upgrade_mode 
GUC is set" should be OK. And we don't want to do anything more 
complicated than that anyway before we know what we need.

(http://archives.postgresql.org/message-id/49425D07.6030701@enterprisedb.com)

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com