On 6 December 2017 at 11:35, Robert Haas <robertmhaas@gmail.com> wrote:
> What are we giving up by explicitly attaching
> the correct index?
The part I don't like about the ATTACH and DETACH of partitioned index
is that it seems to be trying to just follow the syntax we use to
remove a partition from a partitioned table, however, there's a huge
difference between the two, as DETACHing a partition from a
partitioned table leaves the partitioned table in a valid state, it
simply just no longer contains the detached partition. With the
partitioned index, we leave the index in an invalid state after a
DETACH. It can only be made valid again once another leaf index has
been ATTACHED again and that we've verified that all other indexes on
every leaf partition is also there and are valid. If we're going to
use these indexes to answer queries, then it seems like we should try
to keep them valid so that queries can actually use them for
something.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services