Glyn Astill пишет: > WAL is the journal for postgres, so every event that happens goes into the > WAL. Using it for backup or replication simply uses it to replay all events > on the backup / replicated database. > > > >
As I thought, thank you. But why vacuum generates WAL ? As I understand all database changes are already logged.... > ----- Original Message ---- > >> From: Dmitry Melekhov <[EMAIL PROTECTED]> >> To: Simon Riggs <[EMAIL PROTECTED]> >> Cc: pgsql-general@postgresql.org >> Sent: Tuesday, 8 July, 2008 9:54:57 AM >> Subject: Re: [GENERAL] please explain vacuum with WAL >> >> Simon Riggs пишет: >> >>> On Tue, 2008-07-08 at 13:09 +0500, Dmitry Melekhov wrote: >>> >>> >>>> Hello! >>>> >>>> I tried to ask this question in novice list. >>>> Just because there are no replies I try here. >>>> This is really novice question- I'm oracle dba :-) >>>> >>>> >>>> >>>>> I just installed 8.3 with WAL enabled. >>>>> But I can't understand why postgres generated many archive logs during >>>>> vacuum, if WAL is enabled. >>>>> Could you explain? >>>>> >>>>> >>> What do you mean "WAL is enabled"? That's not a term I recognize since >>> WAL is always enabled. >>> >>> >>> >> AFAIK, it can be disabled. May be I'm wrong... >> >>> Best read this >>> http://developer.postgresql.org/pgdocs/postgres/routine-vacuuming.html >>> >>> VACUUM needs to perform writes to clear up, which generates WAL. >>> >>> >>> >> This is what I don't understand. >> I think WAL can be used for point-in-time recovery. >> So, if I have database backup and WAL generated after this backup, I can >> do recovery, this mean WAL already contains all changes to database, >> without vacuum. Could you tell me what is wrong in my sentence? >> >> >> -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
