Re: WIP: store additional info in GIN index

On Sun, Nov 18, 2012 at 4:54 PM, Alexander Korotkov
<aekorotkov@gmail.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.