Re: doubt

Ühel kenal päeval, N, 2007-07-12 kell 14:00, kirjutas Hannu Krosing:
> Ühel kenal päeval, K, 2007-07-11 kell 19:08, kirjutas Greg Smith:
> > On Wed, 11 Jul 2007, Narasimha Rao P.A wrote:
> > 
> > > Does postgreSQL support distributive query processing
> > 
> > Not internally.  It's possible in some situations to split queries up 
> > across multiple nodes using add-on software.  pgpool-II, available at 
> > http://pgfoundry.org/projects/pgpool/ provides an implementation of 
> > distributed queries if your table has a type of key such that you split 
> > across it, but it's relatively immature software 
> 
> Actually it is not "immature" at all, it is used 24/7 doing tens of
> thousands of queries per second :P

uups, I thought you were talking about plproxy ver.2 

http://pgfoundry.org/projects/plproxy

all my ranting is about it, not pgpool II, which is indeed quite new
project ;)

> But it is limited (by design) in what it can do - it is meant to run a
> postgresql _function_ on one or more db hosts based on parameter
> hash(es).
> 
> This can be used as a tool to construct a system which does distributed
> queries, and also to distribute load on small OLTP queries over a set of
> databases.
> 
> > and you would have to 
> > look at it very carefully to see if that parallel query implementation 
> > could fit your needs.
> 
> It has no parallel query implementation by itself (other than a special
> running the same SQL on a set of hosts and merging the results), but you
> definitely can progrem on using pgpool.
> 
> If you need something to distribute queries over a number of hosts
> automatically, there is a commercial data warehousing product (based on
> postgresql) available from greenplum, which does exactly this:
> 
> http://www.greenplum.com/index.php?page=greenplum-database
> 
> 
> > --
> > * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
> > 
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> 
> 
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