mondrian.rolap
Class RolapAggregationManager

java.lang.Object
  mondrian.rolap.RolapAggregationManager

Direct Known Subclasses:

AggregationManager

public abstract class RolapAggregationManager
extends Object

RolapAggregationManager manages all Segments in the system.

The bits of the implementation which depend upon dimensional concepts RolapMember, etc.) live in this class, and the other bits live in the derived class, AggregationManager.

Since:

30 August, 2001

Author:

jhyde

Nested Class Summary

static interface

RolapAggregationManager.PinSet A set of segments which are pinned (prevented from garbage collection) for a short duration as a result of a cache inquiry.

Constructor Summary

protected

RolapAggregationManager() Creates the RolapAggregationManager.

Method Summary

abstract RolapAggregationManager.PinSet	createPinSet() Creates a RolapAggregationManager.PinSet.
CellReader	getCacheCellReader() Returns a CellReader which reads cells from cache.
abstract Object	getCellFromCache(CellRequest request) Retrieves the value of a cell from the cache.
abstract Object	getCellFromCache(CellRequest request, RolapAggregationManager.PinSet pinSet)
abstract String	getDrillThroughSql(DrillThroughCellRequest request, StarPredicate starPredicateSlicer, List<Exp> fields, boolean countOnly) Generates a SQL statement which will return the rows which contribute to this request.
static RolapCacheRegion	makeCacheRegion(RolapStar star, CacheControl.CellRegion region)
static DrillThroughCellRequest	makeDrillThroughRequest(Member[] members, boolean extendedContext, RolapCube cube, List<Exp> fieldsList) Creates a request for the fact-table rows underlying the cell identified by members.
static CellRequest	makeRequest(Member[] members) Creates a request to evaluate the cell identified by members.
static CellRequest	makeRequest(RolapEvaluator evaluator) Creates a request to evaluate the cell identified by the context specified in evaluator.

Methods inherited from class java.lang.Object

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

Constructor Detail

RolapAggregationManager

protected RolapAggregationManager()

Creates the RolapAggregationManager.

Method Detail

makeRequest

public static CellRequest makeRequest(Member[] members)

Creates a request to evaluate the cell identified by members.

If any of the members is the null member, returns null, since there is no cell. If the measure is calculated, returns null.

Parameters:

members - Set of members which constrain the cell

Returns:

Cell request, or null if the requst is unsatisfiable

makeDrillThroughRequest

public static DrillThroughCellRequest makeDrillThroughRequest(Member[] members,
                                                              boolean extendedContext,
                                                              RolapCube cube,
                                                              List<Exp> fieldsList)

Creates a request for the fact-table rows underlying the cell identified by members.

If any of the members is the null member, returns null, since there is no cell. If the measure is calculated, returns null.

Parameters:

members - Set of members which constrain the cell

extendedContext - If true, add non-constraining columns to the query for levels below each current member. This additional context makes the drill-through queries easier for humans to understand.

cube - Cube

Returns:

Cell request, or null if the requst is unsatisfiable

makeRequest

public static CellRequest makeRequest(RolapEvaluator evaluator)

Creates a request to evaluate the cell identified by the context specified in evaluator.

If any of the members from the context is the null member, returns null, since there is no cell. If the measure is calculated, returns null.

Parameters:

evaluator - the cell specified by the evaluator context

Returns:

Cell request, or null if the requst is unsatisfiable

getCellFromCache

public abstract Object getCellFromCache(CellRequest request)

Retrieves the value of a cell from the cache.

Parameters:

request - Cell request

Returns:

Cell value, or null if cell is not in any aggregation in cache, or Util.nullValue if cell's value is null

Pre-condition:

request != null && !request.isUnsatisfiable()

getCellFromCache

public abstract Object getCellFromCache(CellRequest request,
                                        RolapAggregationManager.PinSet pinSet)

getDrillThroughSql

public abstract String getDrillThroughSql(DrillThroughCellRequest request,
                                          StarPredicate starPredicateSlicer,
                                          List<Exp> fields,
                                          boolean countOnly)

Generates a SQL statement which will return the rows which contribute to this request.

Parameters:

request - Cell request

countOnly - If true, return a statment which returns only the count

starPredicateSlicer - A StarPredicate representing slicer positions that could not be represented by the CellRequest, or null if no additional predicate is necessary.

Returns:

SQL statement

makeCacheRegion

public static RolapCacheRegion makeCacheRegion(RolapStar star,
                                               CacheControl.CellRegion region)

getCacheCellReader

public CellReader getCacheCellReader()

Returns a CellReader which reads cells from cache.

createPinSet

public abstract RolapAggregationManager.PinSet createPinSet()

Creates a RolapAggregationManager.PinSet.

Returns:

a new PinSet