Zdenek Kotala wrote: > Bruce Momjian napsal(a): > > Zdenek Kotala wrote: > >> In the last week community made decision about pg_upgrade project and its > >> implementation. I would like to try summarize this conclusion and I add > >> other > >> topic which should be finished for 8.4. > >> > >> Convert on read has been selected as a good way, because it is not > >> invasive and > >> does not limit fresh database. But, this way needs core modification which > >> allows to do online in-place upgrade. It means no online in-place upgrade > >> to 8.4 > >> will be implemented. Sorry about that, but we need move forward and there > >> is not > >> easy way without core modification to do it. > >> > >> As I mentioned manytimes before there are two major issues with convert on > >> read > >> and one small issue. > >> > >> 1) Data does not fit on the new page. It will be solve by pre-upgrade > >> check > >> which reserve space on each page, before upgrade. > > > > Rather than specifying free space as an amount, I was thinking of having > > a boolean like 'ready_for_upgrade' and the system internally would know > > how much free space for each page and tuple. > > You need booth, flag which shows you that the relation/database is ready for > upgrade and free space reservation configuration for each column. System > cannot > know it because PostgreSQL is not oracle :-). It does not know what will > happend > during next version development :-). It have to be setup by pre-upgrade > script.
So every Postgres version will allow space reservation based on the table and page, and the pre-upgrade script will set those values based on the table's columns --- makes sense, and avoids the need for a minor update to Postgres to add new code --- good idea. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
