org.modeshape.graph.query.plan
Class PlanUtil

java.lang.Object
  org.modeshape.graph.query.plan.PlanUtil

public class PlanUtil
extends Object

Utilities for working with PlanNodes.

Nested Class Summary

static class	PlanUtil.ColumnMapping Defines how the view columns are mapped (or resolved) into the columns from the source tables.
protected static class	PlanUtil.RequiredColumnVisitor

Constructor Summary

PlanUtil()

Method Summary

static PlanUtil.ColumnMapping	createMappingFor(Schemata.View view, PlanNode viewPlan)
static PlanUtil.ColumnMapping	createMappingForAliased(SelectorName tableAlias, Schemata.Table table, PlanNode tableSourceNode)
static PlanUtil.ColumnMapping	createMappingForAliased(SelectorName viewAlias, Schemata.View view, PlanNode viewPlan)
static List<Column>	findRequiredColumns(QueryContext context, PlanNode planNode) Collected the minimum set of columns from the supplied table that are required by or used within the plan at the supplied node or above.
static Constraint	replaceReferences(QueryContext context, Constraint constraint, PlanUtil.ColumnMapping mapping, PlanNode node)
static Constraint	replaceReferencesToRemovedSource(QueryContext context, Constraint constraint, Map<SelectorName,SelectorName> rewrittenSelectors)
static DynamicOperand	replaceReferencesToRemovedSource(QueryContext context, DynamicOperand operand, Map<SelectorName,SelectorName> rewrittenSelectors)
static JoinCondition	replaceReferencesToRemovedSource(QueryContext context, JoinCondition joinCondition, Map<SelectorName,SelectorName> rewrittenSelectors)
static void	replaceReferencesToRemovedSource(QueryContext context, PlanNode planNode, Map<SelectorName,SelectorName> rewrittenSelectors)
static DynamicOperand	replaceViewReferences(QueryContext context, DynamicOperand operand, PlanUtil.ColumnMapping mapping, PlanNode node)
static JoinCondition	replaceViewReferences(QueryContext context, JoinCondition joinCondition, PlanUtil.ColumnMapping mapping, PlanNode node)
static void	replaceViewReferences(QueryContext context, PlanNode topOfViewInPlan, PlanUtil.ColumnMapping mappings)

Methods inherited from class java.lang.Object

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

Constructor Detail

PlanUtil

public PlanUtil()

Method Detail

findRequiredColumns

public static List<Column> findRequiredColumns(QueryContext context,
                                               PlanNode planNode)

Collected the minimum set of columns from the supplied table that are required by or used within the plan at the supplied node or above. This method first looks to see if the supplied node is a PlanNode.Type.PROJECT node, and if so immediately returns that node's list of projected columns. Otherwise, this method finds all of the PlanNode.Type.SOURCE nodes below the supplied plan node, and accumulates the set of sources for which the columns are to be found. The method then walks up the plan, looking for references to columns of the supplied table, starting with the supplied node and walking up until a PROJECT node is found or the top of the plan is reached.

The resulting column list will always contain at the front the columns from the nearest PROJECT ancestor, followed by any columns required by criteria. This is done so that the processing of the nearest PROJECT ancestor node can simply use the sublist of each tuple.

Parameters:

context - the query context; may not be null

planNode - the plan node at which the required columns need to be found; may not be null

Returns:

the list of Column objects that are used in the plan; never null but possibly empty if no columns are actually needed

replaceReferencesToRemovedSource

public static void replaceReferencesToRemovedSource(QueryContext context,
                                                    PlanNode planNode,
                                                    Map<SelectorName,SelectorName> rewrittenSelectors)

replaceReferencesToRemovedSource

public static DynamicOperand replaceReferencesToRemovedSource(QueryContext context,
                                                              DynamicOperand operand,
                                                              Map<SelectorName,SelectorName> rewrittenSelectors)

replaceReferencesToRemovedSource

public static Constraint replaceReferencesToRemovedSource(QueryContext context,
                                                          Constraint constraint,
                                                          Map<SelectorName,SelectorName> rewrittenSelectors)

replaceReferencesToRemovedSource

public static JoinCondition replaceReferencesToRemovedSource(QueryContext context,
                                                             JoinCondition joinCondition,
                                                             Map<SelectorName,SelectorName> rewrittenSelectors)

replaceViewReferences

public static void replaceViewReferences(QueryContext context,
                                         PlanNode topOfViewInPlan,
                                         PlanUtil.ColumnMapping mappings)

replaceReferences

public static Constraint replaceReferences(QueryContext context,
                                           Constraint constraint,
                                           PlanUtil.ColumnMapping mapping,
                                           PlanNode node)

replaceViewReferences

public static DynamicOperand replaceViewReferences(QueryContext context,
                                                   DynamicOperand operand,
                                                   PlanUtil.ColumnMapping mapping,
                                                   PlanNode node)

replaceViewReferences

public static JoinCondition replaceViewReferences(QueryContext context,
                                                  JoinCondition joinCondition,
                                                  PlanUtil.ColumnMapping mapping,
                                                  PlanNode node)

createMappingFor

public static PlanUtil.ColumnMapping createMappingFor(Schemata.View view,
                                                      PlanNode viewPlan)

createMappingForAliased

public static PlanUtil.ColumnMapping createMappingForAliased(SelectorName viewAlias,
                                                             Schemata.View view,
                                                             PlanNode viewPlan)

createMappingForAliased

public static PlanUtil.ColumnMapping createMappingForAliased(SelectorName tableAlias,
                                                             Schemata.Table table,
                                                             PlanNode tableSourceNode)