On Tue, May 21, 2019 at 11:15 AM Peter Geoghegan <pg@xxxxxxx> wrote:
On Tue, May 21, 2019 at 11:12 AM Walter Smith <walter@xxxxxxxxxxxx> wrote
> I did a VACUUM overnight and got the following. The thing that stands out to me is that one index (index_unproc_notifications_on_notifiable_type) took 100x longer to scan than the others. That's not the index used in the slow query, though.
What columns are indexed by
index_unproc_notifications_on_notifiable_type, and what are their
datatypes?
It occurs to me that is a somewhat unusual index -- it tracks unprocessed notifications so it gets an insert and delete for every row, and is normally almost empty.
Index "public.index_unproc_notifications_on_notifiable_type"
Column | Type | Definition
-----------------+------------------------+-----------------
notifiable_type | character varying(255) | notifiable_type
btree, for table "public.notifications", predicate (processed = false)
Thanks,
Walter
