org.apache.tajo.plan.rewrite.rules

Class ProjectionPushDownRule

java.lang.Object

org.apache.tajo.plan.visitor.BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule

All Implemented Interfaces:

LogicalPlanRewriteRule, LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

public class ProjectionPushDownRule
extends BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>
implements LogicalPlanRewriteRule

ProjectionPushDownRule deploys expressions in a selection list to proper Projectable nodes. In this process, the expressions are usually pushed down into as lower as possible. It also enables scanners to read only necessary columns.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ProjectionPushDownRule.TargetListManager What is TargetListManager?

Constructor Summary

Constructors

Constructor and Description
ProjectionPushDownRule()

Method Summary

Methods

Modifier and Type	Method and Description
static Target[]	buildGroupByTarget(GroupbyNode groupbyNode, List<Target> groupingKeyTargets, String[] aggEvalNames)
String	getName() It returns the rewrite rule name.
boolean	isEligible(OverridableConf queryContext, LogicalPlan plan) This method checks if this rewrite rule can be applied to a given query plan.
LogicalPlan	rewrite(OverridableConf queryContext, LogicalPlan plan) Updates a logical plan and returns an updated logical plan rewritten by this rule.
LogicalNode	visitFilter(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, SelectionNode node, Stack<LogicalNode> stack)
LogicalNode	visitGroupBy(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, GroupbyNode node, Stack<LogicalNode> stack)
LogicalNode	visitHaving(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, HavingNode node, Stack<LogicalNode> stack)
LogicalNode	visitInsert(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, InsertNode node, Stack<LogicalNode> stack)
LogicalNode	visitJoin(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, JoinNode node, Stack<LogicalNode> stack)
LogicalNode	visitLimit(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, LimitNode node, Stack<LogicalNode> stack)
LogicalNode	visitPartitionedTableScan(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, PartitionedTableScanNode node, Stack<LogicalNode> stack)
LogicalNode	visitProjection(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, ProjectionNode node, Stack<LogicalNode> stack)
LogicalNode	visitRoot(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, LogicalRootNode node, Stack<LogicalNode> stack)
LogicalNode	visitScan(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, ScanNode node, Stack<LogicalNode> stack)
LogicalNode	visitSort(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, SortNode node, Stack<LogicalNode> stack)
LogicalNode	visitTableSubQuery(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context upperContext, LogicalPlan plan, LogicalPlan.QueryBlock block, TableSubQueryNode node, Stack<LogicalNode> stack)
LogicalNode	visitUnion(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, UnionNode node, Stack<LogicalNode> stack)
LogicalNode	visitWindowAgg(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context, LogicalPlan plan, LogicalPlan.QueryBlock block, WindowAggNode node, Stack<LogicalNode> stack)

Methods inherited from class org.apache.tajo.plan.visitor.BasicLogicalPlanVisitor

postHook, preHook, visit, visit, visitAlterTable, visitAlterTablespace, visitCreateDatabase, visitCreateTable, visitDistinctGroupby, visitDropDatabase, visitDropTable, visitEvalExpr, visitExcept, visitIntersect, visitSetSession, visitStoreTable, visitTruncateTable

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectionPushDownRule

public ProjectionPushDownRule()

Method Detail

getName

public String getName()

Description copied from interface: LogicalPlanRewriteRule

It returns the rewrite rule name. It will be used for debugging and building a optimization history.

Specified by:

getName in interface LogicalPlanRewriteRule

Returns:

The rewrite rule name

isEligible

public boolean isEligible(OverridableConf queryContext,
                 LogicalPlan plan)

Description copied from interface: LogicalPlanRewriteRule

This method checks if this rewrite rule can be applied to a given query plan. For example, the selection push down can not be applied to the query plan without any filter. In such case, it will return false.

Specified by:

isEligible in interface LogicalPlanRewriteRule

plan - The plan to be checked

Returns:

True if this rule can be applied to a given plan. Otherwise, false.

rewrite

public LogicalPlan rewrite(OverridableConf queryContext,
                  LogicalPlan plan)
                    throws PlanningException

Description copied from interface: LogicalPlanRewriteRule

Updates a logical plan and returns an updated logical plan rewritten by this rule. It must be guaranteed that the input logical plan is not modified even after rewrite. In other words, the rewrite has to modify an plan copied from the input plan.

Specified by:

rewrite in interface LogicalPlanRewriteRule

plan - Input logical plan. It will not be modified.

Returns:

The rewritten logical plan.

Throws:

PlanningException

visitRoot

public LogicalNode visitRoot(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                    LogicalPlan plan,
                    LogicalPlan.QueryBlock block,
                    LogicalRootNode node,
                    Stack<LogicalNode> stack)
                      throws PlanningException

Specified by:

visitRoot in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitRoot in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitProjection

public LogicalNode visitProjection(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                          LogicalPlan plan,
                          LogicalPlan.QueryBlock block,
                          ProjectionNode node,
                          Stack<LogicalNode> stack)
                            throws PlanningException

Specified by:

visitProjection in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitProjection in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitLimit

public LogicalNode visitLimit(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                     LogicalPlan plan,
                     LogicalPlan.QueryBlock block,
                     LimitNode node,
                     Stack<LogicalNode> stack)
                       throws PlanningException

Specified by:

visitLimit in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitLimit in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitSort

public LogicalNode visitSort(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                    LogicalPlan plan,
                    LogicalPlan.QueryBlock block,
                    SortNode node,
                    Stack<LogicalNode> stack)
                      throws PlanningException

Specified by:

visitSort in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitSort in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitHaving

public LogicalNode visitHaving(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                      LogicalPlan plan,
                      LogicalPlan.QueryBlock block,
                      HavingNode node,
                      Stack<LogicalNode> stack)
                        throws PlanningException

Specified by:

visitHaving in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitHaving in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitWindowAgg

public LogicalNode visitWindowAgg(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                         LogicalPlan plan,
                         LogicalPlan.QueryBlock block,
                         WindowAggNode node,
                         Stack<LogicalNode> stack)
                           throws PlanningException

Specified by:

visitWindowAgg in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitWindowAgg in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitGroupBy

public LogicalNode visitGroupBy(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                       LogicalPlan plan,
                       LogicalPlan.QueryBlock block,
                       GroupbyNode node,
                       Stack<LogicalNode> stack)
                         throws PlanningException

Specified by:

visitGroupBy in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitGroupBy in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

buildGroupByTarget

public static Target[] buildGroupByTarget(GroupbyNode groupbyNode,
                          @Nullable
                          List<Target> groupingKeyTargets,
                          String[] aggEvalNames)

visitFilter

public LogicalNode visitFilter(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                      LogicalPlan plan,
                      LogicalPlan.QueryBlock block,
                      SelectionNode node,
                      Stack<LogicalNode> stack)
                        throws PlanningException

Specified by:

visitFilter in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitFilter in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitJoin

public LogicalNode visitJoin(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                    LogicalPlan plan,
                    LogicalPlan.QueryBlock block,
                    JoinNode node,
                    Stack<LogicalNode> stack)
                      throws PlanningException

Specified by:

visitJoin in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitJoin in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitUnion

public LogicalNode visitUnion(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                     LogicalPlan plan,
                     LogicalPlan.QueryBlock block,
                     UnionNode node,
                     Stack<LogicalNode> stack)
                       throws PlanningException

Specified by:

visitUnion in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitUnion in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitScan

public LogicalNode visitScan(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                    LogicalPlan plan,
                    LogicalPlan.QueryBlock block,
                    ScanNode node,
                    Stack<LogicalNode> stack)
                      throws PlanningException

Specified by:

visitScan in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitScan in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitPartitionedTableScan

public LogicalNode visitPartitionedTableScan(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                                    LogicalPlan plan,
                                    LogicalPlan.QueryBlock block,
                                    PartitionedTableScanNode node,
                                    Stack<LogicalNode> stack)
                                      throws PlanningException

Specified by:

visitPartitionedTableScan in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitPartitionedTableScan in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitTableSubQuery

public LogicalNode visitTableSubQuery(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context upperContext,
                             LogicalPlan plan,
                             LogicalPlan.QueryBlock block,
                             TableSubQueryNode node,
                             Stack<LogicalNode> stack)
                               throws PlanningException

Specified by:

visitTableSubQuery in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitTableSubQuery in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException

visitInsert

public LogicalNode visitInsert(org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context context,
                      LogicalPlan plan,
                      LogicalPlan.QueryBlock block,
                      InsertNode node,
                      Stack<LogicalNode> stack)
                        throws PlanningException

Specified by:

visitInsert in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Overrides:

visitInsert in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.ProjectionPushDownRule.Context,LogicalNode>

Throws:

PlanningException