Re: Merge join vs merge semi join against primary key

On 09/10/15 20:52, Sean Rhea wrote:
[...]
>    ->  Index Scan using customers_pkey on customers  (cost=0.00..64192.97
> rows=184 width=8) (actual time=103.354..126.459 rows=359 loops=1)
>          Filter: (group_id = 45)
>          Rows Removed by Filter: 141684
>  Total runtime: 146.659 ms
[...]
>    ->  Index Scan using customers_pkey on customers o  (cost=0.00..63836.61
> rows=836 width=8) (actual time=159.840..201915.765 rows=7672 loops=1)
>          Filter: (group_id = 45)
>          Rows Removed by Filter: 212699113
>  Total runtime: 201995.044 ms

Are you sure the customers table was the same?
--
Jeremy