Package org.apache.calcite.rel.core

Class SemiJoin

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.BiRel

org.apache.calcite.rel.core.Join

org.apache.calcite.rel.core.EquiJoin

org.apache.calcite.rel.core.SemiJoin

All Implemented Interfaces:

java.lang.Cloneable, RelOptNode, RelNode

Direct Known Subclasses:

EnumerableSemiJoin

public class SemiJoin
extends EquiJoin

Relational expression that joins two relational expressions according to some condition, but outputs only columns from the left input, and eliminates duplicates.

The effect is something like the SQL IN operator.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.rel.RelNode

RelNode.Context

Field Summary

Fields inherited from class org.apache.calcite.rel.core.EquiJoin

leftKeys, rightKeys

Fields inherited from class org.apache.calcite.rel.core.Join

condition, joinType, variablesSet

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

left, right

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

digest, id, rowType, traitSet

Constructor Summary

Constructors

Constructor	Description
SemiJoin(RelOptCluster cluster, RelTraitSet traitSet, RelNode left, RelNode right, RexNode condition, ImmutableIntList leftKeys, ImmutableIntList rightKeys)	Creates a SemiJoin.

Method Summary

Modifier and Type	Method	Description
RelOptCost	computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq)	Returns the cost of this plan (not including children).
SemiJoin	copy(RelTraitSet traitSet, RexNode condition, RelNode left, RelNode right, JoinRelType joinType, boolean semiJoinDone)	Creates a copy of this join, overriding condition, system fields and inputs.
static SemiJoin	create(RelNode left, RelNode right, RexNode condition, ImmutableIntList leftKeys, ImmutableIntList rightKeys)	Creates a SemiJoin.
RelDataType	deriveRowType()
double	estimateRowCount(RelMetadataQuery mq)	Returns an estimate of the number of rows this relational expression will return.

Methods inherited from class org.apache.calcite.rel.core.EquiJoin

analyzeCondition, getLeftKeys, getRightKeys

Methods inherited from class org.apache.calcite.rel.core.Join

accept, copy, createJoinType, deriveJoinRowType, estimateJoinedRows, explainTerms, getChildExps, getCondition, getJoinType, getSystemFieldList, getVariablesSet, isSemiJoinDone, isValid

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

childrenAccept, getInputs, getLeft, getRight, replaceInput

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

accept, collectVariablesSet, collectVariablesUsed, computeDigest, computeSelfCost, explain, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getQuery, getRelTypeName, getRows, getRowType, getTable, getTraitSet, getVariablesStopped, isDistinct, isKey, isValid, metadata, onRegister, recomputeDigest, register, sole, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

SemiJoin

public SemiJoin(RelOptCluster cluster,
                RelTraitSet traitSet,
                RelNode left,
                RelNode right,
                RexNode condition,
                ImmutableIntList leftKeys,
                ImmutableIntList rightKeys)

Creates a SemiJoin.

Use create(org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode, org.apache.calcite.rex.RexNode, org.apache.calcite.util.ImmutableIntList, org.apache.calcite.util.ImmutableIntList) unless you know what you're doing.

Parameters:

cluster - cluster that join belongs to

traitSet - Trait set

left - left join input

right - right join input

condition - join condition

leftKeys - left keys of the semijoin

rightKeys - right keys of the semijoin

Method Detail

create

public static SemiJoin create(RelNode left,
                              RelNode right,
                              RexNode condition,
                              ImmutableIntList leftKeys,
                              ImmutableIntList rightKeys)

Creates a SemiJoin.

copy

public SemiJoin copy(RelTraitSet traitSet,
                     RexNode condition,
                     RelNode left,
                     RelNode right,
                     JoinRelType joinType,
                     boolean semiJoinDone)

Description copied from class: Join

Creates a copy of this join, overriding condition, system fields and inputs.

General contract as RelNode.copy(org.apache.calcite.plan.RelTraitSet, java.util.List<org.apache.calcite.rel.RelNode>).

Specified by:

copy in class Join

Parameters:

traitSet - Traits

condition - Condition

left - Left input

right - Right input

joinType - Join type

semiJoinDone - Whether this join has been translated to a semi-join

Returns:

Copy of this join

computeSelfCost

public RelOptCost computeSelfCost(RelOptPlanner planner,
                                  RelMetadataQuery mq)

Description copied from interface: RelNode

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getNonCumulativeCost(org.apache.calcite.rel.RelNode), which gives plugins a chance to override the rel's default ideas about cost.

Specified by:

computeSelfCost in interface RelNode

Overrides:

computeSelfCost in class Join

Parameters:

planner - Planner for cost calculation

mq - Metadata query

Returns:

Cost of this plan (not including children)

estimateRowCount

public double estimateRowCount(RelMetadataQuery mq)

Description copied from interface: RelNode

Returns an estimate of the number of rows this relational expression will return.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getRowCount(org.apache.calcite.rel.RelNode), which gives plugins a chance to override the rel's default ideas about row count.

Specified by:

estimateRowCount in interface RelNode

Overrides:

estimateRowCount in class Join

Parameters:

mq - Metadata query

Returns:

Estimate of the number of rows this relational expression will return

deriveRowType

public RelDataType deriveRowType()

In the case of semi-join, the row type consists of columns from left input only.

Overrides:

deriveRowType in class Join