Index-only plan has been merged.

[Taewoo Kim <wa...@gmail.com>]

Hi All,

Finally, the index-only plan branch has been merged. Thanks to all who have
reviewed this patch set. Here are a few things that I would like to post.

- The Index-only plan will be triggered on a B+ tree or an R tree (point or
rectangle field only) index. The field should be a closed-type field. A
field cannot be an open-type field.

- Only the secondary key and/or the primary key are used in a selection or
join predicate. Also, only those fields (SK or PK) are used afterward
(e.g., returning only those fields).

- If you see an error and see "UNION_ALL" operator and two paths in the
plan, it might be related to the index-only plan. For this case, before a
query, you can put " set noindexonly 'true'; " to bypass the index-only
plan as a temporary measure. Of course, please file an issue. :-)

Best,
Taewoo