RE: AW: Backup, restore & pg_dump
От | Mikheev, Vadim |
---|---|
Тема | RE: AW: Backup, restore & pg_dump |
Дата | |
Msg-id | 8F4C99C66D04D4118F580090272A7A23018D6E@SECTORBASE1 обсуждение исходный текст |
Ответ на | AW: Backup, restore & pg_dump (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>) |
Список | pgsql-hackers |
> > BTW, avoiding writes is base WAL feature, ie - it'll be > > implemented in 7.1. > > Wow, great, I thought first step was only to avoid sync :-) ? If syncs are not required then why to do write call? > > > No, but rollforward is currently the main feature, no ? > > > > I'm going to rollback changes on abort in 7.1. Seems I've > > mentioned both redo and UNDO (without compensation records) > > AM methods many times. > > I don't think that I misunderstood anything here. If the commit > record is in the tx log this tx will have to be rolled forward, and > not aborted. Of course open tx's on abort will be rolled back. > But this roll forward for committed tx could be a starting point, no? Currently records inserted by aborted transactions remain in db untill vacuum. I try to rollback changes - ie *delete* inserted tuples on abort (though could do not do this), - isn't there some difference now? > > > Does it make sense to ship WAL without using it's currently > > > main feature ? > > > > Sorry, but it's not always possible to have all at once. > > Sorry, my main point was not to argument against WAL in 7.1, > but to state, that backup/restore would be very important. Yes but I'm not able to do this work. And note that with WAL in 7.1 we could add backup/restore in any version > 7.1 (eg 7.1.1). > > (BTW, replication server prototype announced by Pgsql, Inc > > could be used for incremental backup) > > Yes, that could be a good starting point for rollforward if it is > based on WAL. It's not. > We should not call this tx log business "Incremental backup" > an incremental backup scans all pages, and backs > them up if they changed in respect to the last higher level backup. > (full backup, level 1 backup, level 2 backup ....) > Oracle only uses this chargon, since they don't have such a > backup, and want to fool their customer's managers. > All other DB companies make correct use of the wording > "incremental backup" in the above sense. Scanning *all* pages?! Not the best approach imho. Or did you meant scanning log to get last *committed" changes to all pages - ie some kind of log compression? Vadim
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