org.apache.drill.exec.planner.sql.handlers

Class FindLimit0Visitor

java.lang.Object

org.apache.calcite.rel.RelShuttleImpl

org.apache.drill.exec.planner.sql.handlers.FindLimit0Visitor

All Implemented Interfaces:

org.apache.calcite.rel.RelShuttle

public class FindLimit0Visitor
extends org.apache.calcite.rel.RelShuttleImpl

Visitor that will identify whether the root portion of the RelNode tree contains a limit 0 pattern. In this case, we inform the planner settings that this plan should be run as a single node plan to reduce the overhead associated with executing a schema-only query.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FindLimit0Visitor.RelDataTypeReader Reader for column names and types.

Field Summary

Fields inherited from class org.apache.calcite.rel.RelShuttleImpl

stack

Method Summary

Modifier and Type	Method and Description
static DrillRel	addLimitOnTopOfLeafNodes(DrillRel rel)
static boolean	containsLimit0(org.apache.calcite.rel.RelNode rel) Check if the root portion of the tree contains LIMIT(0).
static DrillRel	getDirectScanRelIfFullySchemaed(org.apache.calcite.rel.RelNode rel) If all field types of the given node are recognized types and honored by execution, then this method returns the tree: DrillDirectScanRel(field types).
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalAggregate aggregate)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalIntersect intersect)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalJoin join)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalMinus minus)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalSort sort)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.logical.LogicalUnion union)
org.apache.calcite.rel.RelNode	visit(org.apache.calcite.rel.RelNode other)

Methods inherited from class org.apache.calcite.rel.RelShuttleImpl

visit, visit, visit, visit, visit, visit, visit, visit, visitChild, visitChildren

Methods inherited from class java.lang.Object

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

Method Detail

getDirectScanRelIfFullySchemaed

public static DrillRel getDirectScanRelIfFullySchemaed(org.apache.calcite.rel.RelNode rel)

If all field types of the given node are recognized types and honored by execution, then this method returns the tree: DrillDirectScanRel(field types). Otherwise, the method returns null.

Parameters:

rel - calcite logical rel tree

Returns:

drill logical rel tree

containsLimit0

public static boolean containsLimit0(org.apache.calcite.rel.RelNode rel)

Check if the root portion of the tree contains LIMIT(0).

Parameters:

rel - rel node tree

Returns:

true if the root portion of the tree contains LIMIT(0)

addLimitOnTopOfLeafNodes

public static DrillRel addLimitOnTopOfLeafNodes(DrillRel rel)

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalSort sort)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.RelNode other)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalAggregate aggregate)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalIntersect intersect)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalJoin join)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalMinus minus)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl

visit

public org.apache.calcite.rel.RelNode visit(org.apache.calcite.rel.logical.LogicalUnion union)

Specified by:

visit in interface org.apache.calcite.rel.RelShuttle

Overrides:

visit in class org.apache.calcite.rel.RelShuttleImpl