Re: AWS forcing PG upgrade from v9.6 a disaster

On 5/28/21 2:48 PM, Dean Gibson (DB Administrator) wrote:

What sticks out for me are these two scans, which balloon from 50-60 
heap fetches to 1.5M each.

>                       ->  Nested Loop  (cost=0.29..0.68 rows=1 width=7) 
> (actual time=0.003..0.004 rows=1 loops=1487153)
>                             Join Filter: ("_IsoCountry".iso_alpha2 = 
> "_Territory".country_id)
>                             Rows Removed by Join Filter: 0
>                             ->  Index Only Scan using 
> "_IsoCountry_iso_alpha2_key" on "_IsoCountry"  (cost=0.14..0.38 rows=1 
> width=3) (actual time=0.001..0.002 rows=1 loops=1487153)
>                                   Index Cond: (iso_alpha2 = 
> "_GovtRegion".country_id)
>                                   Heap Fetches: 1487153
>                             ->  Index Only Scan using "_Territory_pkey" 
> on "_Territory"  (cost=0.14..0.29 rows=1 width=7) (actual 
> time=0.001..0.001 rows=1 loops=1487153)
>                                   Index Cond: (territory_id = 
> "_GovtRegion".territory_id)
>                                   Heap Fetches: 1550706

How did you load the database? pg_dump -> psql/pg_restore?

If so, did you perform a VACUUM FREEZE after the load?


Regards, Jan

-- 
Jan Wieck
Postgres User since 1994