Calculate width and depth

pkg/logql/count_min_sketch.go

@@ -13,6 +13,9 @@ import (
 
 const (
 	CountMinSketchVectorType = "CountMinSketchVector"
+
+	epsilon = 0.0001
+	delta = 0.05
 )
 
 type CountMinSketchVector struct {
@@ -123,7 +126,7 @@ func (e *countMinSketchVectorAggEvaluator) Next() (bool, int64, StepResult) {
 	}
 	vec := r.SampleVector()
 
-	f, _ := sketch.NewCountMinSketch(0, 0) // TODO: handle error and size sketch
+	f, _ := sketch.NewCountMinSketchFromErroAndProbability(epsilon, delta)
 
 	result := CountMinSketchVector{
 		T:       ts,

pkg/logql/sketch/cms.go

@@ -19,6 +19,12 @@ func NewCountMinSketch(w, d uint32) (*CountMinSketch, error) {
 	}, nil
 }
 
+func NewCountMinSketchFromErroAndProbability(epsilon float64, delta float64) (*CountMinSketch, error) {
+	width := math.Ceil(math.E / epsilon)
+	depth := math.Ceil(math.Log( 1.0 / delta))
+	return NewCountMinSketch(uint32(width), uint32(depth))
+}
+
 func make2dslice(col, row uint32) [][]uint32 {
 	ret := make([][]uint32, row)
 	for i := range ret {