Re: PostgreSQL derivatives

Seth,

> My understanding is that the MPP vendors using PostgreSQL and Ingres are
> not *significantly* altering the software other than to, essentially,
> turn off reliance on indexes.  They're then adding extensions that are
> proprietary and not, except in the case of GridSQL, open source.  Is my
> understanding correct?

Actually, that's incorrect.  Greenplum, Yahoo and Netezza all made
substantial alterations to the PostgreSQL code.  Greenplum has
re-written the executor and bulk loader, and seems to be on the way to
re-writing the planner entirely.  Yahoo and Netezza each pretty much
ripped out everthing except for the parser and a few other bits (Yahoo
kept the Function code, for example), but replaced a majority of the
PostgreSQL code.

I wouldn't classify GridSQL as MPP.  It's strictly PP.

--Josh Berkus