org.apache.tajo.plan.rewrite.rules

Class FilterPushDownRule

java.lang.Object

org.apache.tajo.plan.visitor.BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

org.apache.tajo.plan.rewrite.rules.FilterPushDownRule

All Implemented Interfaces:

LogicalPlanRewriteRule, LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

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

This rule tries to push down all filter conditions into logical nodes as lower as possible. It is likely to significantly reduces the intermediate data.

Constructor Summary

Constructors

Constructor and Description
FilterPushDownRule()

Method Summary

Methods

Modifier and Type	Method and Description
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.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, SelectionNode selNode, Stack<LogicalNode> stack)
LogicalNode	visitGroupBy(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, GroupbyNode groupbyNode, Stack<LogicalNode> stack)
LogicalNode	visitJoin(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, JoinNode joinNode, Stack<LogicalNode> stack)
LogicalNode	visitProjection(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, ProjectionNode projectionNode, Stack<LogicalNode> stack)
LogicalNode	visitScan(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, ScanNode scanNode, Stack<LogicalNode> stack)
LogicalNode	visitTableSubQuery(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, TableSubQueryNode node, Stack<LogicalNode> stack)
LogicalNode	visitUnion(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, UnionNode unionNode, Stack<LogicalNode> stack)
LogicalNode	visitWindowAgg(org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext context, LogicalPlan plan, LogicalPlan.QueryBlock block, WindowAggNode winAggNode, 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, visitHaving, visitInsert, visitIntersect, visitLimit, visitPartitionedTableScan, visitRoot, visitSetSession, visitSort, visitStoreTable, visitTruncateTable

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterPushDownRule

public FilterPushDownRule()

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

visitFilter

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

Specified by:

visitFilter in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitFilter in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitJoin

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

Specified by:

visitJoin in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitJoin in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitTableSubQuery

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

Specified by:

visitTableSubQuery in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitTableSubQuery in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitUnion

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

Specified by:

visitUnion in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitUnion in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitProjection

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

Specified by:

visitProjection in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitProjection in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitWindowAgg

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

Specified by:

visitWindowAgg in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitWindowAgg in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitGroupBy

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

Specified by:

visitGroupBy in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitGroupBy in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException

visitScan

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

Specified by:

visitScan in interface LogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Overrides:

visitScan in class BasicLogicalPlanVisitor<org.apache.tajo.plan.rewrite.rules.FilterPushDownRule.FilterPushDownContext,LogicalNode>

Throws:

PlanningException