Re: On columnar storage - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: On columnar storage
Date
Msg-id 20150612185014.GO133018@postgresql.org
Whole thread Raw
In response to Re: On columnar storage  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-hackers
Merlin Moncure wrote:
> On Thu, Jun 11, 2015 at 6:03 PM, Alvaro Herrera
> <alvherre@2ndquadrant.com> wrote:
> > We hope to have a chance to discuss this during the upcoming developer
> > unconference in Ottawa.  Here are some preliminary ideas to shed some
> > light on what we're trying to do.
> 
> Quick thought.  We already support out of line columnar storage in a
> fashion with 'toast'.  Obviously that's a long way from where you want
> to go, but have you ruled out extending that system?

TOAST uses pointers in the heap row.  A toasted column is still present
in the heap -- there's no way to get across the 1600-column limitation
if we rely on anything stored in the heap.  Hence the design of the
feature at hand is that the columnar storage somehow "points" to the
heap, rather than the other way around.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



pgsql-hackers by date:

Previous
From: Peter Geoghegan
Date:
Subject: Re: Further issues with jsonb semantics, documentation
Next
From: Thom Brown
Date:
Subject: Re: Hash index creation warning