Why is my mean much more bigger than my Execution Time using hyperfine to benchmark my query performance?
QUERY PLAN GroupAggregate (cost=21267.11..21286.98 rows=461 width=31) (actual time=1.711..1.712 rows=1 loops=1) Group Key: (date_trunc(‘month’::text, timezone(‘Europe/Berlin’::text, m.”timestamp”))), d.sub_type -> Sort (cost=21267.11..21268.91 rows=719 width=35) (actual time=1.564..1.591 rows=719 loops=1) Sort Key: (date_trunc(‘month’::text, timezone(‘Europe/Berlin’::text, m.”timestamp”))), d.sub_type Sort Method: quicksort Memory: 69kB -> Nested Loop (cost=70.03..21233.00 rows=719 width=35) (actual time=0.483..1.454 rows=719 loops=1) -> Index Scan using idx_devices_id on devices d (cost=0.28..8.30 […]