Re: Running Postgres Daemons with same data files

On Thu, 11 Dec 2003, Matt Clark wrote:

> Well I wasn't joking.
>
> If you want to get the files on disk into a state where they can be modified by a different postmaster, then you need
toshut the 
> current postmaster down.  In theory, maybe, if you only want the second postmaster to have read access, then you
coulddisconnect 
> all users from the current postmaster and stop accepting any more connections, but I wouldn't do it if I were you.
>
> Maybe I'm missing the point.  The only other answer is:
>
> commit;
>
> Because for postgres commit *means* commit the transaction to disk.  Of course if you're using a NAS then who knows
whetherthe 
> files have _really_ been written to disk after an fsync.  Postgres just has to believe what the operating system
tellsit... 

Of course, they might just get written to the WAL... the *only* way to
get the files into a consistent, safe state is to stop the server.
Sorry.

> > Don't joke, this for stopping the Postgres Server. I want close the
> > files in between the database operations. I am looking for some SQL
> > command like in Mysql command is 'flush tables'. what's in postgres?
> >
> > regards
> > bhartendu
> >
> > On Thu, 2003-12-11 at 16:56, Matt Clark wrote:
> > > > I got all your points, thanks for such a great discussion, Now the last
> > > > thing I want is how can I close the data files and flush the cache into
> > > > the data files. How can I do this in postgresql????
> > >
> > > pg_ctl stop
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 4: Don't 'kill -9' the postmaster
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
>
>                http://www.postgresql.org/docs/faqs/FAQ.html
>

--

Sam Barnett-Cormack
Software Developer                           |  Student of Physics & Maths
UK Mirror Service (http://www.mirror.ac.uk)  |  Lancaster University