Class RolapAggregator.BaseAggor

All Implemented Interfaces:
Aggregator, EnumeratedValues.Value
Direct Known Subclasses:
RolapAggregator.AvgFromAvg, RolapAggregator.AvgFromSum, RolapAggregator.SumFromAvg
Enclosing class:
RolapAggregator

public abstract static class RolapAggregator.BaseAggor extends RolapAggregator
This is the base class for implementing aggregators over sum and average columns in an aggregate table. These differ from the above aggregators in that these require not oly the operand to create the aggregation String expression, but also, the aggregate table's fact count column expression. These aggregators are NOT singletons like the above aggregators; rather, each is different because of the fact count column expression.
  • Field Details

    • factCountExpr

      protected final String factCountExpr
  • Constructor Details

    • BaseAggor

      protected BaseAggor(String name, String factCountExpr)
  • Method Details

    • aggregate

      public Object aggregate(Evaluator evaluator, TupleList members, Calc exp)
      Description copied from interface: Aggregator
      Applies this aggregator to an expression over a set of members and returns the result.
      Parameters:
      evaluator - Evaluation context
      members - List of members, not null
      exp - Expression to evaluate
      Returns:
      result of applying this aggregator to a set of members/tuples
    • alwaysRequiresFactColumn

      public abstract boolean alwaysRequiresFactColumn()
    • getScalarExpression

      public abstract String getScalarExpression(String operand)