Re: Is index deduplication active on an index

Even I’m looking for the same.

On Sat, Aug 24, 2024 at 12:55 AM Craig Milhiser <craig(at)milhiser(dot)com> wrote:

> Is there a way I can determine if index deduplication is active on the
> indexes?
>
> I inherited a database that has been upgraded from v12 to 13 to 16. I
> checked the upgrade scripts used and there was not a reindex run during the
> upgrades. Someone may have run a reindex over the years.
>
> Then I can reindex if needed those indexes created prior to v13.
>
> I looked in pg_index but I did not find a field. Perhaps it is in a flag
> in indoption but I did not see that in the definition in
> src/include/catalog/pg_index.h. I see the allequalimage flag to protect the
> conditions described in the documentation. But I do not know if that flag
> is reused to signify this index has been evaluated for deduplication due to
> a reindex and it is safe. A comment in _bt_allequalimage in
> src/backend/access/nbtree/nbtutils.c says the flag is stored in the index
> meta page. Is there a way to find index deduplication is active for an
> index from a postgresql client?
>
> Thanks
>
>