2009/3/24 Tom Lane <tgl@postgresql.org>:
> Implement "fastupdate" support for GIN indexes, in which we try to accumulate
> multiple index entries in a holding area before adding them to the main index
> structure. This helps because bulk insert is (usually) significantly faster
> than retail insert for GIN.
>
> This patch also removes GIN support for amgettuple-style index scans. The
> API defined for amgettuple is difficult to support with fastupdate, and
> the previously committed partial-match feature didn't really work with
> it either. We might eventually figure a way to put back amgettuple
> support, but it won't happen for 8.4.
>
> catversion bumped because of change in GIN's pg_am entry, and because
> the format of GIN indexes changed on-disk (there's a metapage now,
> and possibly a pending list).
Will this break pg_migrator?
...Robert