Thread: 2 instances of postmaster with different data directories

2 instances of postmaster with different data directories

From
"surabhi.ahuja"
Date:
 Hi,
 
I am going to integrate my dtabase into a system. That system also has another database and uses postgres.
 
However they have their own data directory and start postmaster by specifying that.
 
I have seen that it is possible to run multiple postmasters on multiple ports by specifying diffrent data directories.
 
But we are still to decide if we should go with the above approach....or is it better to have just one data directory and one instance of postmaster on the default port.
 
any amount of info will be valuable.
 
thanks,
regards
 
Surabhi Ahuja

Re: 2 instances of postmaster with different data directories

From
Richard Huxton
Date:
surabhi.ahuja wrote:
> Hi,
>
> I am going to integrate my dtabase into a system. That system also
> has another database and uses postgres.
>
> However they have their own data directory and start postmaster by
> specifying that.
>
> I have seen that it is possible to run multiple postmasters on
> multiple ports by specifying diffrent data directories.
>
> But we are still to decide if we should go with the above
> approach....or is it better to have just one data directory and one
> instance of postmaster on the default port.

Two instances will be less efficient:
  - two separate areas of shared-memory
  - two caches
  - possible I/O competition (particularly with WAL I'd expect)
  - twice as many upgrades needed when patches are released
but will allow:
  - two different versions of PostgreSQL
  - separate user lists

Does that help?
--
   Richard Huxton
   Archonet Ltd