public class RolapNativeCrossJoin extends RolapNativeSet
NativeEvaluatorthat 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 queries like
SELECT ... NON EMTPY Crossjoin( [product].[name].members, [customer].[name].members) ON ROWS FROM [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
RolapNativeSet.SchemaReaderWithMemberReaderAvailable, RolapNativeSet.SetConstraint, RolapNativeSet.SetEvaluator
|Constructor and Description|
|Modifier and Type||Method and Description|
Returns whether certain member types (e.g.
crossJoinArgFactory, flushCache, isPreferInterpreter, overrideContext
protected boolean restrictMemberTypes()
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. This is ok, if the superflous members are filtered out in java code afterwards.
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