CursorSpecification Class

About the CursorSpecification class

A CursorSpecification specifies certain aspects of the behavior of the Cursor that corresponds to it. You do not create a CursorSpecification directly. You pass a Source to the createCursorManagerSpecification method of a DataProvider and the CursorManagerSpecification returned has a root CursorSpecification for that Source. If the Source has outputs, the CursorManagerSpecification also has a child CursorSpecification for the values of the Source and one for each output of the Source.

With CursorSpecification methods, you can do the following:

• Get the Source that corresponds to the CursorSpecification.

• Get or set the default fetch size for the corresponding Cursor.

• On a CompoundCursorSpecification, specify that the default fetch size is set on the children of the corresponding Cursor.

• Specify that the OLAP service should calculate the extent of a Cursor.

• Find out if calculating the extent is specified.

• Specify that the OLAP service should calculate the starting or ending position of the current value of the corresponding Cursor in its parent Cursor. If you know the starting and ending positions of a value in the parent, then you can determine how many faster varying elements the parent Cursor has for that value.

• Find out if calculating the starting or ending position of the current value of the corresponding Cursor in its parent is specified.

• Accept a CursorSpecificationVisitor.

For more information, see "About Cursor Positions and Extent" and "About Fetch Sizes and Fetch Blocks".

The Oracle OLAP API defines the following three classes in the oracle.olapi.data.source package:

CursorSpecification	An abstract superclass that implements methods inherited by its subclasses.
ValueCursorSpecification	A CursorSpecification for a Source that has values and no outputs.
CompoundCursorSpecification	A CursorSpecification for a Source that has one or more outputs. A CompoundCursorSpecification has component child CursorSpecification objects.

A Cursor has the same structure as its CursorManagerSpecification. For every ValueCursorSpecification or CompoundCursorSpecification of a CursorManagerSpecification, a Cursor has a corresponding ValueCursor or CompoundCursor. To be able to get certain information or behavior from a Cursor, your application must specify that it wants that information or behavior by calling methods on the corresponding CursorSpecification before it creates the Cursor.

CursorSpecification methods

All CursorSpecification objects have the following methods. The set methods specify the behavior of the Cursor that corresponds to the CursorSpecification.

Method	Return Value
acceptVisitor	An Object. This method accepts a CursorSpecificationVisitor. For more information, see the Oracle9i OLAP Services OLAP API Reference
getDefaultFetchSize	The fetch size set as the default on the CursorSpecification.
getSource	The Source for the CursorSpecification.
isExtentCalculationSpecified	A boolean that indicates whether the CursorSpecification specifies the calculation of the extent of the Cursor.
isParentEndCalculationSpecified	A boolean that indicates whether the CursorSpecification specifies the calculation of the ending position in the parent Cursor for the current value of the child Cursor.
isParentStartCalculationSpecified	A boolean that indicates whether the CursorSpecification specifies the calculation of the starting position in the parent Cursor for the current value of the child Cursor.
setDefaultFetchSize	Void. This method specifies a default fetch size for the Cursor. If a default fetch size is specified on a CursorSpecification, then you can change the fetch size on the Cursor.
setExtentCalculationSpecified	Void. This method specifies whether to calculate the extent of the Cursor.
setParentEndCalculationSpecified	Void. This method specifies whether to calculate the ending position in the parent Cursor for the current value of the Cursor.
setParentStartCalculationSpecified	Void. This method specifies whether to calculate the starting position in the parent Cursor for the current value of the Cursor.

CompoundCursorSpecification methods

In addition to the methods it inherits from CursorSpecification, a CompoundCursorSpecification has the following methods:

Method	Return Value
acceptVisitor	An Object. This method accepts a CursorSpecificationVisitor.
getOutputs	A List of the CursorSpecification objects that are the outputs of this CompoundCursorSpecification.
getValueCursorSpecification	The ValueCursorSpecification for this CompoundCursorSpecification.
specifyDefaultFetchSizeOnChildren	Void. This method specifies that the default fetch size is set on the child CursorSpecification objects of this CompoundCursorSpecification. This method has two versions, one that supplies a fetch size and one that does not.

ValueCursorSpecification methods

In addition to the methods it inherits from CursorSpecification, a ValueCursorSpecification has an override of the following method:

Method	Return Value
acceptVisitor	An Object. This method accepts a CursorSpecificationVisitor.