Class SegmentationExtensions

Wrapper for segmentation-related extension methods. You shouldn't ever need to refer directly to this class.

Inheritance

Object

SegmentationExtensions

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: Mangrove.MetricSetTransformers.Segmentation

Assembly: MetricSetTransformers.dll

Syntax

public static class SegmentationExtensions

Methods

ColumnReferenceToSegmentTupleMap(IEnumerable<Expression>, IEnumerable<(ColumnReference expr, Int32 group, Boolean flag)>)

Collect all the ColumnReference represented by pairs of strings (table name, column name) that depend (are children of) a given list of segment expressions.

Declaration

public static IDictionary<(string Table, string Expression), (ColumnReference, int, bool)> ColumnReferenceToSegmentTupleMap(this IEnumerable<Expression> expressions, IEnumerable<(ColumnReference expr, int group, bool flag)> segmentTuples)

Parameters

Type	Name	Description
IEnumerable<Expression>	expressions
IEnumerable<ValueTuple<ColumnReference, Int32, Boolean>>	segmentTuples

Returns

Type	Description
IDictionary<ValueTuple<String, String>, ValueTuple<ColumnReference, Int32, Boolean>>

Remarks

Because the output of the class is used in expression visitors where the expressions will change, but not their names, it is better to identify the column references with a pair of corresponding string names.

PropagateAggregands(MetricsPlan, IEnumerable<ColumnReference>)

Creates and propagates Aggregand from a Table to all of its children. Result is a collection of ColumnReference wrapping the newly created aggregands plus the original ColumnReference themselves.

Declaration

public static ISet<ColumnReference> PropagateAggregands(this MetricsPlan plan, IEnumerable<ColumnReference> startingExpressions)

Parameters

Type	Name	Description
MetricsPlan	plan
IEnumerable<ColumnReference>	startingExpressions

Returns

Type	Description
ISet<ColumnReference>

Remarks

Used for segmentation. If a column defines a segment (so is used in "group by" statement) we need to group by the value of this column all the way up to the top level of aggregation.