mondrian.rolap
Class RolapDimension

java.lang.Object
  mondrian.olap.OlapElementBase
      mondrian.olap.DimensionBase
          mondrian.rolap.RolapDimension

All Implemented Interfaces:

Dimension, OlapElement

Direct Known Subclasses:

RolapCubeDimension

 class RolapDimension
extends DimensionBase

RolapDimension implements Dimensionfor a ROLAP database.

Topic: Dimension ordinals

RolapEvaluator needs each dimension to have an ordinal, so that it can store the evaluation context as an array of members.

The ordinal of a dimension within a particular cube is found by calling getOrdinal(Cube). Ordinals are contiguous and zero-based. Zero is always the [Measures] dimension.

A dimension may be either shared or private to a particular cube. The dimension object doesn't actually know which; Schema has a list of shared hierarchies (Schema.getSharedHierarchies()), and Cube has a list of dimensions (Cube.getDimensions()).

If a dimension is shared between several cubes, the Dimensionobjects which represent them may (or may not be) the same. (That's why there's no getCube() method.)

Furthermore, since members are created by a MemberReaderwhich belongs to the RolapHierarchy, you will the members will be the same too. For example, if you query [Product].[Beer] from the Sales and Warehouse cubes, you will get the same RolapMemberobject. (RolapSchema.mapSharedHierarchyToReader holds the mapping. I don't know whether it's still necessary.)

Since:

10 August, 2001

Author:

jhyde

Field Summary

Fields inherited from class mondrian.olap.DimensionBase

description, dimensionType, hierarchies, highCardinality, name, uniqueName

Fields inherited from class mondrian.olap.OlapElementBase

caption

Fields inherited from interface mondrian.olap.Dimension

MEASURES_NAME, MEASURES_UNIQUE_NAME

Constructor Summary

RolapDimension(RolapSchema schema, RolapCube cube, MondrianDef.Dimension xmlDimension, MondrianDef.CubeDimension xmlCubeDimension)
Creates a dimension from an XML definition.

RolapDimension(Schema schema, String name, DimensionType dimensionType, boolean highCardinality)

Method Summary

Hierarchy	getHierarchy() Returns the hierarchy of an expression.
protected org.apache.log4j.Logger	getLogger()
int	getOrdinal(Cube cube) Returns dimension's ordinal within a given cube.
Schema	getSchema() Returns the schema this dimension belongs to.
(package private) void	init(MondrianDef.CubeDimension xmlDimension) Initializes a dimension within the context of a cube.
(package private) RolapHierarchy	newHierarchy(String subName, boolean hasAll)

Methods inherited from class mondrian.olap.DimensionBase

getDescription, getDimension, getDimensionType, getHierarchies, getName, getQualifiedName, getUniqueName, isHighCardinality, isMeasures, lookupChild, lookupChild, usesDimension

Methods inherited from class mondrian.olap.OlapElementBase

clone, computeHashCode, equals, equals, getCaption, hashCode, setCaption, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface mondrian.olap.OlapElement

getCaption

Constructor Detail

RolapDimension

RolapDimension(Schema schema,
               String name,
               DimensionType dimensionType,
               boolean highCardinality)

RolapDimension

RolapDimension(RolapSchema schema,
               RolapCube cube,
               MondrianDef.Dimension xmlDimension,
               MondrianDef.CubeDimension xmlCubeDimension)

Creates a dimension from an XML definition.

Pre-condition:

schema != null

Method Detail

getLogger

protected org.apache.log4j.Logger getLogger()

Specified by:

getLogger in class OlapElementBase

init

void init(MondrianDef.CubeDimension xmlDimension)

Initializes a dimension within the context of a cube.

newHierarchy

RolapHierarchy newHierarchy(String subName,
                            boolean hasAll)

getHierarchy

public Hierarchy getHierarchy()

Returns the hierarchy of an expression.

In this case, the expression is a dimension, so the hierarchy is the dimension's default hierarchy (its first).

Specified by:

getHierarchy in interface OlapElement

Overrides:

getHierarchy in class DimensionBase

getOrdinal

public int getOrdinal(Cube cube)

Description copied from interface: Dimension

Returns dimension's ordinal within a given cube. The [Measures] always has ordinal 0.

getSchema

public Schema getSchema()

Description copied from interface: Dimension

Returns the schema this dimension belongs to.