Re: Simplifying wal_sync_method - Mailing list pgsql-hackers

From Magnus Hagander
Subject Re: Simplifying wal_sync_method
Date
Msg-id 6BCB9D8A16AC4241919521715F4D8BCE6C785F@algol.sollentuna.se
Whole thread Raw
In response to Simplifying wal_sync_method  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: Simplifying wal_sync_method  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
List pgsql-hackers
> > > Now thinking about it, the guy had corrupt table, not WAL log.
> > > How is WAL->tables synched?  Does the 'wal_sync_method'
> > > affect it or not?
> >
> > I *think* it always fsyncs() there as it is now, but I'm
> not 100% sure.
>
> No.  If fsync is off, then no fsync is done to the data files
> on checkpoint either.  (See mdsync() on src/backend/storage/smgr/md.c)

Right, but we're not talking fsync=off, we're talking when you are using
fdatasync, O_SYNC etc.

If you turn off fsync you're on your own, no matter the OS or other
settings...

//Magnus


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