* Add benchmark for query_range with topk
Modify sample data so values within a metric differ
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Optimise topk where k==1
In this case we don't need a heap to keep track of values; just a single
slot is fine.
Simplify the initialization of the heap: since all cases start off as a
single-item heap we can just assign the value directly.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Allow at least one slot in results for topk, quantile
k isn't set for quantile, but we need space to start collecting values
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
7d105277fe