Re: restoring a shadow

Turbo Fredriksson wrote:
> 
> In my  attempts of  trying to increase  performance and  redundancy, I
> have trying to get rServ replication to work.
> 
> I have  successfully been able  to replicate between two  databases on
> localhost.
> 
>         test            -> Main db
>         test_slave      -> Slave db
> 
> The 'test'  database is  located in PGDATA  (/var/lib/pgsql/data), and
> 'test_slave' in  PGDATA2 (/var/lib/pgsql/data2). Works  fine (although
> I'm a little unhappy about the replication speed).
> 
> Now, I'd  like to have  PGDATA in a  ram disk (we're only  expecting a
> maximum of  10-15Mb of data). The  problem is if the  machine is being
> reset  (hardware  vice)  or if  it  crashes.   Then  the ram  disk  is
> lost. This is where PGDATA2 comes into play...

Why bother with a RAM disk? If you only have a few megabytes, why not just
allocate a large number of buffers to PostgreSQL. Most, if not everything
should end up in RAM. Up your shared memory limites and give tones to
PostgreSQL. We do that where I work, and I have seen 100% cache hit rate on
some queries.