Re: Querying an index's btree version

On Wed, Mar 11, 2020 at 1:26 PM Darren Lafreniere
<dlafreniere@onezero.com> wrote:
> We've read that PG 12 has improved btree index support, and that the latest internal btree version was bumped from 3
to4. Is it possible to query the btree version that a particular index is using? We'd like to automatically start a
concurrentre-index if we detect any btree indexes are still on version 3. 

It's possible, but you have to install the superuser-only pageinspect
extension. Here is how you'd determine that an index called
'pg_aggregate_fnoid_index' is on version 4:

regression=# create extension pageinspect;
CREATE EXTENSION
regression=# select version from bt_metap('pg_aggregate_fnoid_index');
 version
---------
       4
(1 row)

--
Peter Geoghegan