Re: What do Oracle, DB2, etc. actually *do*?

On Saturday 19 March 2005 13:13, Josh Berkus wrote:
> Neil, William,
> Actually, Sybase tackles this issue a different way .... one that, I may
> add, could be done with Slony-I with a little back-end glue.   Basically,
> they make each replicated node the "master" of one subset of data; for
> example, if it's a personnel database, then all personnel records for each
> office location are "mastered" at that office location.   If you're
> updating records at your current location (which is assumed to be the
> majority of updates) it goes in direct and cascades out to the other
> servers; if you update records for a different office, it goes to their
> server across the wire and cascades back to you asynchronously.
>
> Obviously, this only works for distributed applications where such
> partitioning of data is reasonable, but that actually covers a lot of
> real-world WAN distributed databases.   Point-of-Sale, for example, as well
> as HR.

ISTR someone doing something like this with Slony... where they were doing all 
inserts/updates to a local table that replicaed out to other offices but 
using either a view that encapsulated all tables or using inheritence between 
the local (child) table and a parent table (encapsulating all tables) to do 
selects to see changes.  I think this was an inventory system... anyone 
remember for sure? 

-- 
Robert Treat
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL