Re: [Sequoia] PostgreSQL Documentation of High Availability

Markus Schiltknecht wrote:
> Hello Emmanuel,
> 
> Emmanuel Cecchet wrote:
> >>> Even here I think that there is a common misconception between 
> >>> performance and scalability. Most people think that by having 
> >>> multiple nodes their query will run faster which is obviously wrong 
> >>> if your original workload does not saturate a single node. 
> >>
> >> Sure. Do you think that should be made clearer?
> > Yes, I think so because this is a very common belief that we experience 
> > with new users.
> 
> Okay, I have forwarded that to Bruce, who's editing the documentation 
> (and is a native English speaker). I'm not sure how we can cover this, 
> as we are very general in our description.

OK, updated:

  Multi-Server Parallel Query Execution
  

   
    Many of the above solutions allow multiple servers to handle
    multiple queries, but none allow a single query to use multiple
    servers to complete faster.  This solution allows multiple
    servers to work concurrently on a single query.  This is usually
    accomplished by splitting the data among servers and having
    each server execute its part of the query and return results
    to a central server where they are combined and returned to
    the user.  Pgpool-II has this capability.

-- 
  Bruce Momjian   bruce@momjian.us
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +