Re: WIP: store additional info in GIN index

On 12/4/12 9:34 AM, Robert Haas 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.

Is there a reason not to create this as a new type of index? "GIN2" or
whatever?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com