mondrian.rolap.agg
Class SegmentLoader

java.lang.Object
  mondrian.rolap.agg.SegmentLoader

public class SegmentLoader
extends Object

The SegmentLoader queries database and loads the data into the given set of segments.

It reads a segment of measure, where columns are constrained to values. Each entry in values can be null, meaning don't constrain, or can have several values. For example, getSegment({Unit_sales}, {Region, State, Year}, {"West"}, {"CA", "OR", "WA"}, null}) returns sales in states CA, OR and WA in the Western region, for all years.

Since:

24 May 2007

Author:

Thiyagu

Constructor Summary

SegmentLoader()

Method Summary

(package private) SqlStatement	createExecuteSql(GroupingSetsList groupingSetsList, List<StarPredicate> compoundPredicateList) Creates and executes a SQL statement to retrieve the set of cells specified by a GroupingSetsList.
(package private) SortedSet<Comparable<?>>[]	getDistinctValueWorkspace(int arity)
(package private) List<RolapStar.Column[]>	getGroupingColumnsList(RolapStar.Column[] detailedBatchColumns, List<GroupingSet> aggBatchDetails)
(package private) BitKey	getRollupBitKey(int arity, Object[] row, int k) Generates bit key representing roll up columns
void	load(List<GroupingSet> groupingSets, RolapAggregationManager.PinSet pinnedSegments, List<StarPredicate> compoundPredicateList) Loads data for all the segments of the GroupingSets.
(package private) List<Object[]>	loadData(SqlStatement stmt, GroupingSetsList groupingSetsList)
(package private) List<Object[]>	processData(SqlStatement stmt, boolean[] axisContainsNull, SortedSet<Comparable<?>>[] axisValueSets, GroupingSetsList groupingSetsList)
(package private) void	setFailOnStillLoadingSegments(GroupingSetsList groupingSetsList)
(package private) boolean	useSparse(boolean sparse, int n, List<Object[]> rows)

Methods inherited from class java.lang.Object

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

Constructor Detail

SegmentLoader

public SegmentLoader()

Method Detail

load

public void load(List<GroupingSet> groupingSets,
                 RolapAggregationManager.PinSet pinnedSegments,
                 List<StarPredicate> compoundPredicateList)

Loads data for all the segments of the GroupingSets. If the grouping sets list contains more than one Grouping Set then data is loaded using the GROUP BY GROUPING SETS sql. Else if only one grouping set is passed in the list data is loaded without using GROUP BY GROUPING SETS sql. If the database does not support grouping sets SqlQuery.Dialect.supportsGroupingSets() then grouping sets list should always have only one element in it.

For example, if list has 2 grouping sets with columns A, B, C and B, C respectively, then the SQL will be "GROUP BY GROUPING SETS ((A, B, C), (B, C))".

Else if the list has only one grouping set then sql would be without grouping sets.

The groupingSets list should be topological order, with more detailed higher-level grouping sets occuring first. In other words, the first element of the list should always be the detailed grouping set (default grouping set), followed by grouping sets which can be rolled-up on this detailed grouping set. In the example (A, B, C) is the detailed grouping set and (B, C) is rolled-up using the detailed.

Parameters:

groupingSets - List of grouping sets whose segments are loaded

pinnedSegments - Pinned segments

setFailOnStillLoadingSegments

void setFailOnStillLoadingSegments(GroupingSetsList groupingSetsList)

useSparse

boolean useSparse(boolean sparse,
                  int n,
                  List<Object[]> rows)

createExecuteSql

SqlStatement createExecuteSql(GroupingSetsList groupingSetsList,
                              List<StarPredicate> compoundPredicateList)

Creates and executes a SQL statement to retrieve the set of cells specified by a GroupingSetsList.

This method may be overridden in tests.

Parameters:

groupingSetsList - Grouping

Returns:

An executed SQL statement, or null

processData

List<Object[]> processData(SqlStatement stmt,
                           boolean[] axisContainsNull,
                           SortedSet<Comparable<?>>[] axisValueSets,
                           GroupingSetsList groupingSetsList)
                     throws SQLException

Throws:

SQLException

getRollupBitKey

BitKey getRollupBitKey(int arity,
                       Object[] row,
                       int k)

Generates bit key representing roll up columns

loadData

List<Object[]> loadData(SqlStatement stmt,
                        GroupingSetsList groupingSetsList)
                  throws SQLException

Throws:

SQLException

getGroupingColumnsList

List<RolapStar.Column[]> getGroupingColumnsList(RolapStar.Column[] detailedBatchColumns,
                                                List<GroupingSet> aggBatchDetails)

getDistinctValueWorkspace

SortedSet<Comparable<?>>[] getDistinctValueWorkspace(int arity)