Re: WIP: store additional info in GIN index

On Tue, Dec 4, 2012 at 9:34 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Sun, Nov 18, 2012 at 4:54 PM, Alexander Korotkov
> <aekorotkov(at)gmail(dot)com> wrote:
> > Patch completely changes storage in posting lists and leaf pages of
> posting
> > trees. It uses varbyte encoding for BlockNumber and OffsetNumber.
> > BlockNumber are stored incremental in page. Additionally one bit of
> > OffsetNumber is reserved for additional information NULL flag. To be
> able to
> > find position in leaf data page quickly patch introduces small index in
> the
> > end of page.
>
> This sounds like it means that this would break pg_upgrade, about
> which I'm not too keen. Ideally, we'd like to have a situation where
> new indexes have additional capabilities, but old indexes are still
> usable for things that they could do before. I am not sure whether
> that's a realistic goal.

This means to have two versions of code which deals with posting trees and
lists. For me it seems unlikely we have resources for maintenance of this.

------
With best regards,
Alexander Korotkov.