On Wednesday, February 8, 2023, Philippe VIEGAS <p.vie...@loxodata.com> wrote:
> Hi all, > > I was wondering why the index statistics usage were not reflecting the > index usage for primary key constraint validation ? > > When we create a table with a primary key, PostgreSQL creates a Btree > index for the validation of this constraint : index is defined unique > (indisunique=t) and primary (indisprimary=t) from the pg_index and pg_class > catalogs. > > Inserting data on the above created table and selecting based on the > primary key column will increment the idx_scan from `pg_stat_user_indexes` > view. > > The select produces the index scan, not the insert. The insert doesn’t scan, it populates and aborts if that population fails. It doesn’t check first. David J.
