org.apache.drill.exec.physical.impl.join

Class JoinUtils

java.lang.Object

org.apache.drill.exec.physical.impl.join.JoinUtils

public class JoinUtils
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JoinUtils.JoinCategory

Field Summary

Fields

Modifier and Type	Field and Description
static String	FAILED_TO_PLAN_CARTESIAN_JOIN

Constructor Summary

Constructors

Constructor and Description
JoinUtils()

Method Summary

Modifier and Type	Method and Description
static void	addLeastRestrictiveCasts(LogicalExpression[] leftExpressions, VectorAccessible leftBatch, LogicalExpression[] rightExpressions, VectorAccessible rightBatch, FragmentContext context) Utility method used by joins to add implicit casts on one of the sides of the join condition in case the two expressions have different types.
static UnsupportedRelOperatorException	cartesianJoinPlanningException() Creates new exception for queries that cannot be planned due to presence of cartesian or inequality join.
static Comparator	checkAndReturnSupportedJoinComparator(JoinCondition condition)
static boolean	checkCartesianJoin(org.apache.calcite.rel.RelNode relNode) Check if the given RelNode contains any Cartesian join.
static boolean	checkCartesianJoin(org.apache.calcite.rel.RelNode relNode, List<Integer> leftKeys, List<Integer> rightKeys, List<Boolean> filterNulls) Check if the given RelNode contains any Cartesian join.
static JoinUtils.JoinCategory	getJoinCategory(org.apache.calcite.rel.RelNode left, org.apache.calcite.rel.RelNode right, org.apache.calcite.rex.RexNode condition, List<Integer> leftKeys, List<Integer> rightKeys, List<Boolean> filterNulls)
static boolean	hasScalarSubqueryInput(org.apache.calcite.rel.RelNode left, org.apache.calcite.rel.RelNode right) Utility method to check if a any of input RelNodes is provably scalar.
static boolean	isScalarSubquery(org.apache.calcite.rel.RelNode root) Utility method to check if a subquery (represented by its root RelNode) is provably scalar.

Methods inherited from class java.lang.Object

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

Field Detail

FAILED_TO_PLAN_CARTESIAN_JOIN

public static final String FAILED_TO_PLAN_CARTESIAN_JOIN

Constructor Detail

JoinUtils

public JoinUtils()

Method Detail

checkAndReturnSupportedJoinComparator

public static Comparator checkAndReturnSupportedJoinComparator(JoinCondition condition)

checkCartesianJoin

public static boolean checkCartesianJoin(org.apache.calcite.rel.RelNode relNode,
                                         List<Integer> leftKeys,
                                         List<Integer> rightKeys,
                                         List<Boolean> filterNulls)

Check if the given RelNode contains any Cartesian join. Return true if find one. Otherwise, return false.

Parameters:

relNode - the RelNode to be inspected.

leftKeys - a list used for the left input into the join which has equi-join keys. It can be empty or not (but not null), this method will clear this list before using it.

rightKeys - a list used for the right input into the join which has equi-join keys. It can be empty or not (but not null), this method will clear this list before using it.

filterNulls - The join key positions for which null values will not match.

Returns:

Return true if the given relNode contains Cartesian join. Otherwise, return false

checkCartesianJoin

public static boolean checkCartesianJoin(org.apache.calcite.rel.RelNode relNode)

Check if the given RelNode contains any Cartesian join. Return true if find one. Otherwise, return false.

Parameters:

relNode - RelNode instance to be inspected

Returns:

Return true if the given relNode contains Cartesian join. Otherwise, return false

addLeastRestrictiveCasts

public static void addLeastRestrictiveCasts(LogicalExpression[] leftExpressions,
                                            VectorAccessible leftBatch,
                                            LogicalExpression[] rightExpressions,
                                            VectorAccessible rightBatch,
                                            FragmentContext context)

Utility method used by joins to add implicit casts on one of the sides of the join condition in case the two expressions have different types.

Parameters:

leftExpressions - array of expressions from left input into the join

leftBatch - left input record batch

rightExpressions - array of expressions from right input into the join

rightBatch - right input record batch

context - fragment context

isScalarSubquery

public static boolean isScalarSubquery(org.apache.calcite.rel.RelNode root)

Utility method to check if a subquery (represented by its root RelNode) is provably scalar. Currently only aggregates with no group-by are considered scalar. In the future, this method should be generalized to include more cases and reconciled with Calcite's notion of scalar.

Parameters:

root - The root RelNode to be examined

Returns:

True if the root rel or its descendant is scalar, False otherwise

getJoinCategory

public static JoinUtils.JoinCategory getJoinCategory(org.apache.calcite.rel.RelNode left,
                                                     org.apache.calcite.rel.RelNode right,
                                                     org.apache.calcite.rex.RexNode condition,
                                                     List<Integer> leftKeys,
                                                     List<Integer> rightKeys,
                                                     List<Boolean> filterNulls)

hasScalarSubqueryInput

public static boolean hasScalarSubqueryInput(org.apache.calcite.rel.RelNode left,
                                             org.apache.calcite.rel.RelNode right)

Utility method to check if a any of input RelNodes is provably scalar.

Parameters:

left - the RelNode to be inspected.

right - the RelNode to be inspected.

Returns:

Return true if any of the given RelNodes is provably scalar. Otherwise, return false

cartesianJoinPlanningException

public static UnsupportedRelOperatorException cartesianJoinPlanningException()

Creates new exception for queries that cannot be planned due to presence of cartesian or inequality join.

Returns:

new UnsupportedRelOperatorException instance