mondrian.rolap
Class RolapHierarchy

java.lang.Object
  mondrian.olap.OlapElementBase
      mondrian.olap.HierarchyBase
          mondrian.rolap.RolapHierarchy

All Implemented Interfaces:

Hierarchy, OlapElement

Direct Known Subclasses:

RolapCubeHierarchy

public class RolapHierarchy
extends HierarchyBase

RolapHierarchy implements Hierarchy for a ROLAP database.

Since:

10 August, 2001

Author:

jhyde

Nested Class Summary

static class	RolapHierarchy.LimitedRollupMember Substitute for a member in a hierarchy whose rollup policy is 'partial' or 'hidden'.
protected static class	RolapHierarchy.RolapCalculatedMeasure Calculated member which is also a measure (that is, a member of the [Measures] dimension).
(package private) static class	RolapHierarchy.RolapNullMember A RolapNullMember is the null member of its hierarchy.

Field Summary

(package private) Type	memberType Type for members of this hierarchy.
protected RolapLevel	nullLevel The level that the null member belongs too.
protected MondrianDef.RelationOrJoin	relation
protected MondrianDef.Hierarchy	xmlHierarchy

Fields inherited from class mondrian.olap.HierarchyBase

allLevelName, allMemberName, description, dimension, hasAll, levels, name, subName, uniqueName

Fields inherited from class mondrian.olap.OlapElementBase

caption

Constructor Summary

RolapHierarchy(RolapDimension dimension, MondrianDef.Hierarchy xmlHierarchy, MondrianDef.CubeDimension xmlCubeDimension)
Creates a RolapHierarchy.

RolapHierarchy(RolapDimension dimension, String subName, boolean hasAll)

Method Summary

(package private) void	addToFrom(SqlQuery query, MondrianDef.Expression expression) Adds to the FROM clause of the query the tables necessary to access the members of this hierarchy.
(package private) void	addToFrom(SqlQuery query, RolapStar.Table table) Adds a table to the FROM clause of the query.
protected int	computeHashCode() Computes this object's hash code.
(package private) RolapDimension	createClosedPeerDimension(RolapLevel src, MondrianDef.Closure clos, MondrianDef.CubeDimension xmlDimension) Builds a dimension which maps onto a table holding the transitive closure of the relationship for this parent-child level.
Member	createMember(Member parent, Level level, String name, Formula formula) Creates a member of this hierarchy.
(package private) MemberReader	createMemberReader(Role role) Creates a member reader which enforces the access-control profile of role.
boolean	equals(Object o)
(package private) Exp	getAggregateChildrenExpression() Returns an expression which will compute a member's value by aggregating its children.
(package private) String	getAlias()
RolapMember	getAllMember() Returns the 'all' member.
Member	getDefaultMember() Returns the default member of this hierarchy.
protected org.apache.log4j.Logger	getLogger()
(package private) MemberReader	getMemberReader()
Member	getNullMember() Returns a special member representing the "null" value.
MondrianDef.RelationOrJoin	getRelation()
RolapSchema	getRolapSchema()
String	getSharedHierarchyName() Returns the name of the source hierarchy, if this hierarchy is shared, otherwise null.
(package private) MondrianDef.Relation	getUniqueTable() If this hierarchy has precisely one table, returns that table; if this hierarchy has no table, return the cube's fact-table; otherwise, returns null.
MondrianDef.Hierarchy	getXmlHierarchy()
(package private) void	init(MondrianDef.CubeDimension xmlDimension) Initializes a hierarchy within the context of a cube.
boolean	isRagged() A hierarchy is ragged if it contains one or more levels with hidden members.
(package private) RolapLevel	newMeasuresLevel()
void	setDefaultMember(Member defaultMember) Sets default member of this Hierarchy.
(package private) void	setMemberReader(MemberReader memberReader)
(package private) boolean	tableExists(String tableName)

Methods inherited from class mondrian.olap.HierarchyBase

equals, getAllLevelName, getAllMemberName, getDescription, getDimension, getHierarchy, getLevels, getName, getQualifiedName, getSubName, getUniqueName, hasAll, lookupChild, lookupChild

Methods inherited from class mondrian.olap.OlapElementBase

clone, 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

Field Detail

xmlHierarchy

protected MondrianDef.Hierarchy xmlHierarchy

relation

protected MondrianDef.RelationOrJoin relation

memberType

final Type memberType

Type for members of this hierarchy. Set once to avoid excessive newing.

nullLevel

protected final RolapLevel nullLevel

The level that the null member belongs too.

Constructor Detail

RolapHierarchy

RolapHierarchy(RolapDimension dimension,
               String subName,
               boolean hasAll)

RolapHierarchy

RolapHierarchy(RolapDimension dimension,
               MondrianDef.Hierarchy xmlHierarchy,
               MondrianDef.CubeDimension xmlCubeDimension)

Creates a RolapHierarchy.

Parameters:

dimension - the dimension this hierarchy belongs to

xmlHierarchy - the xml object defining this hierarchy

xmlCubeDimension - the xml object defining the cube dimension for this object

Method Detail

getLogger

protected org.apache.log4j.Logger getLogger()

Specified by:

getLogger in class OlapElementBase

equals

public boolean equals(Object o)

Overrides:

equals in class OlapElementBase

computeHashCode

protected int computeHashCode()

Description copied from class: OlapElementBase

Computes this object's hash code. Called at most once.

Overrides:

computeHashCode in class OlapElementBase

Returns:

hash code

init

void init(MondrianDef.CubeDimension xmlDimension)

Initializes a hierarchy within the context of a cube.

setMemberReader

void setMemberReader(MemberReader memberReader)

getMemberReader

MemberReader getMemberReader()

newMeasuresLevel

RolapLevel newMeasuresLevel()

getUniqueTable

MondrianDef.Relation getUniqueTable()

If this hierarchy has precisely one table, returns that table; if this hierarchy has no table, return the cube's fact-table; otherwise, returns null.

tableExists

boolean tableExists(String tableName)

getRolapSchema

public RolapSchema getRolapSchema()

getRelation

public MondrianDef.RelationOrJoin getRelation()

getXmlHierarchy

public MondrianDef.Hierarchy getXmlHierarchy()

getDefaultMember

public Member getDefaultMember()

Description copied from interface: Hierarchy

Returns the default member of this hierarchy.

If a hierarchy is subject to access-control, the default member may not be visible, so use SchemaReader.getHierarchyDefaultMember(mondrian.olap.Hierarchy).

getNullMember

public Member getNullMember()

Description copied from interface: Hierarchy

Returns a special member representing the "null" value. This never occurs on an axis, but may occur if functions such as Lead, NextMember and ParentMember walk off the end of the hierarchy.

getAllMember

public RolapMember getAllMember()

Returns the 'all' member.

createMember

public Member createMember(Member parent,
                           Level level,
                           String name,
                           Formula formula)

Description copied from interface: Hierarchy

Creates a member of this hierarchy. If this is the measures hierarchy, a calculated member is created, and formula must not be null.

getAlias

String getAlias()

getSharedHierarchyName

public String getSharedHierarchyName()

Returns the name of the source hierarchy, if this hierarchy is shared, otherwise null.

If this hierarchy is a public -- that is, it belongs to a dimension which is a usage of a shared dimension -- then sharedHierarchyName holds the unique name of the shared hierarchy; otherwise it is null.

Suppose this hierarchy is "Weekly" in the dimension "Order Date" of cube "Sales", and that "Order Date" is a usage of the "Time" dimension. Then sharedHierarchyName will be "[Time].[Weekly]".

addToFrom

void addToFrom(SqlQuery query,
               MondrianDef.Expression expression)

Adds to the FROM clause of the query the tables necessary to access the members of this hierarchy. If expression is not null, adds the tables necessary to compute that expression.

This method is idempotent: if you call it more than once, it only adds the table(s) to the FROM clause once.

Parameters:

query - Query to add the hierarchy to

expression - Level to qualify up to; if null, qualifies up to the topmost ('all') expression, which may require more columns and more joins

addToFrom

void addToFrom(SqlQuery query,
               RolapStar.Table table)

Adds a table to the FROM clause of the query. If table is not null, adds the table. Otherwise, add the relation on which this hierarchy is based on.

This method is idempotent: if you call it more than once, it only adds the table(s) to the FROM clause once.

Parameters:

query - Query to add the hierarchy to

table - table to add to the query

createMemberReader

MemberReader createMemberReader(Role role)

Creates a member reader which enforces the access-control profile of role.

This method may not be efficient, so the caller should take care not to call it too often. A cache is a good idea.

Pre-condition:

role != null

Post-condition:

return != null

isRagged

public boolean isRagged()

A hierarchy is ragged if it contains one or more levels with hidden members.

Specified by:

isRagged in class HierarchyBase

getAggregateChildrenExpression

Exp getAggregateChildrenExpression()

Returns an expression which will compute a member's value by aggregating its children.

It is efficient to share one expression between all calculated members in a parent-child hierarchy, so we only need need to validate the expression once.

createClosedPeerDimension

RolapDimension createClosedPeerDimension(RolapLevel src,
                                         MondrianDef.Closure clos,
                                         MondrianDef.CubeDimension xmlDimension)

Builds a dimension which maps onto a table holding the transitive closure of the relationship for this parent-child level.

This method is triggered by the MondrianDef.Closure element in a schema, and is only meaningful for a parent-child hierarchy.

When a Schema contains a parent-child Hierarchy that has an associated closure table, Mondrian creates a parallel internal Hierarchy, called a "closed peer", that refers to the closure table. This is indicated in the schema at the level of a Level, by including a Closure element. The closure table represents the transitive closure of the parent-child relationship.

The peer dimension, with its single hierarchy, and 3 levels (all, closure, item) really 'belong to' the parent-child level. If a single hierarchy had two parent-child levels (however unlikely this might be) then each level would have its own auxiliary dimension.

For example, in the demo schema the [HR].[Employee] dimension contains a parent-child hierarchy:

 <Dimension name="Employees" foreignKey="employee_id">
   <Hierarchy hasAll="true" allMemberName="All Employees"
         primaryKey="employee_id">
     <Table name="employee"/>
     <Level name="Employee Id" type="Numeric" uniqueMembers="true"
            column="employee_id" parentColumn="supervisor_id"
            nameColumn="full_name" nullParentValue="0">
       <Closure parentColumn="supervisor_id" childColumn="employee_id">
          <Table name="employee_closure"/>
       </Closure>
       ...
 

The internal closed peer Hierarchy has this structure:

 <Dimension name="Employees" foreignKey="employee_id">
     ...
     <Hierarchy name="Employees$Closure"
         hasAll="true" allMemberName="All Employees"
         primaryKey="employee_id" primaryKeyTable="employee_closure">
       <Join leftKey="supervisor_id" rightKey="employee_id">
         <Table name="employee_closure"/>
         <Table name="employee"/>
       </Join>
       <Level name="Closure"  type="Numeric" uniqueMembers="false"
           table="employee_closure" column="supervisor_id"/>
       <Level name="Employee" type="Numeric" uniqueMembers="true"
           table="employee_closure" column="employee_id"/>
     </Hierarchy>
 

Note that the original Level with the Closure produces two Levels in the closed peer Hierarchy: a simple peer (Employee) and a closed peer (Closure).

Parameters:

src - a parent-child Level that has a Closure clause

clos - a Closure clause

Returns:

the closed peer Level in the closed peer Hierarchy

setDefaultMember

public void setDefaultMember(Member defaultMember)

Sets default member of this Hierarchy.

Parameters:

defaultMember - Default member