Re: WAL to RAW devices ? - Mailing list pgsql-general

From Alex Vinogradovs
Subject Re: WAL to RAW devices ?
Date
Msg-id 1188604176.6082.49.camel@localhost
Whole thread Raw
In response to Re: WAL to RAW devices ?  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: WAL to RAW devices ?
Re: WAL to RAW devices ?
List pgsql-general
WAL segments already have their structure. Filesystem would be an
overhead, plus I meantioned access to the same storage from
multiple hosts - no filesystem mounting, synchronization and
other problems.

I figured PG folks aren't interested in adding enterprise-level storage
functionality (movable tablespaces, raw devices for tablespaces, etc),
thus I foresee the model described as the only way to achieve somewhat
decent performance in a stressed environment.


On Fri, 2007-08-31 at 19:21 -0400, Tom Lane wrote:
> Alex Vinogradovs <AVinogradovs@clearpathnet.com> writes:
> >  The idea is to have say 2 raw devices which would be used as 2 WAL
> > segments (round-robin). RO servers will go after the one that's not used
> > at a given time with something like xlogdump utility and produce INSERT
> > statements to be then executed locally. After that import is done, a
> > command will be issued to the WO server to switch to the other segment
> > so that the cycle can repeat.
>
> Why would you insist on these being raw devices?  Do you enjoy writing
> filesystems from scratch?
>
>             regards, tom lane

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