mondrian.rolap
Class RolapNativeCrossJoin

java.lang.Object
  mondrian.rolap.RolapNative
      mondrian.rolap.RolapNativeSet
          mondrian.rolap.RolapNativeCrossJoin

public class RolapNativeCrossJoin
extends RolapNativeSet

creates a NativeEvaluator that evaluates NON EMPTY CrossJoin in SQL. The generated SQL will join the dimension tables with the fact table and return all combinations that have a corresponding row in the fact table. The current context (slicer) is used for filtering (WHERE clause in SQL). This very effective computes queris like

   select ...
   NON EMTPY crossjoin([product].[name].members, [customer].[name].members) on rows
   froms [Sales]
   where ([store].[store #14])
 

where both, customer.name and product.name have many members, but the resulting crossjoin only has few.

The implementation currently can not handle sets containting parent/child hierarchies, ragged hierarchies, calculated members and the ALL member. Otherwise all

Since:

Nov 21, 2005

Author:

av

Nested Class Summary

(package private) static class

RolapNativeCrossJoin.NonEmptyCrossJoinConstraint Constraint that restricts the result to the current context.

Nested classes/interfaces inherited from class mondrian.rolap.RolapNativeSet

RolapNativeSet.CrossJoinArg, RolapNativeSet.DescendantsCrossJoinArg, RolapNativeSet.MemberListCrossJoinArg, RolapNativeSet.SchemaReaderWithMemberReaderAvailable, RolapNativeSet.SetConstraint, RolapNativeSet.SetEvaluator

Nested classes/interfaces inherited from class mondrian.rolap.RolapNative

RolapNative.Listener, RolapNative.NativeEvent, RolapNative.TupleEvent

Field Summary

Fields inherited from class mondrian.rolap.RolapNativeSet

LOGGER

Fields inherited from class mondrian.rolap.RolapNative

listener

Constructor Summary

RolapNativeCrossJoin()

Method Summary

(package private) NativeEvaluator	createEvaluator(RolapEvaluator evaluator, FunDef fun, Exp[] args) If function can be implemented in SQL, returns a NativeEvaluator that computes the result; otherwise returns null.
protected boolean	restrictMemberTypes() Returns whether certain member types(e.g.

Methods inherited from class mondrian.rolap.RolapNativeSet

checkCrossJoin, checkCrossJoinArg, checkDescendants, checkEnumeration, checkLevelMembers, checkMemberChildren, isPreferInterpreter, isSimpleLevel, overrideContext, useHardCache

Methods inherited from class mondrian.rolap.RolapNative

getListener, isEnabled, setEnabled, setListener

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RolapNativeCrossJoin

public RolapNativeCrossJoin()

Method Detail

restrictMemberTypes

protected boolean restrictMemberTypes()

Description copied from class: RolapNativeSet

Returns whether certain member types(e.g. calculated members) should disable native SQL evaluation for expressions containing them.

If true, expressions containing calculated members will be evaluated by the interpreter, instead of using SQL. If false, calc members will be ignored and the computation will be done in SQL, returning more members than requested.

Specified by:

restrictMemberTypes in class RolapNativeSet

createEvaluator

NativeEvaluator createEvaluator(RolapEvaluator evaluator,
                                FunDef fun,
                                Exp[] args)

Description copied from class: RolapNative

If function can be implemented in SQL, returns a NativeEvaluator that computes the result; otherwise returns null.

Specified by:

createEvaluator in class RolapNative