org.apache.calcite.rel.core

Class Minus

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.core.SetOp

org.apache.calcite.rel.core.Minus

All Implemented Interfaces:

Cloneable, RelOptNode, RelNode

Direct Known Subclasses:

EnumerableMinus, JdbcRules.JdbcMinus, LogicalMinus

public abstract class Minus
extends SetOp

Relational expression that returns the rows of its first input minus any matching rows from its other inputs.

Corresponds to the SQL EXCEPT operator.

If "all" is true, then multiset subtraction is performed; otherwise, set subtraction is performed (implying no duplicates in the results).

Field Summary

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

all, inputs, kind

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

digest, id, rowType, traitSet

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Minus(RelInput input) Creates a Minus by parsing serialized output.
	Minus(RelOptCluster cluster, RelTraitSet traits, List<RelNode> inputs, boolean all)

Method Summary

Methods

Modifier and Type	Method and Description
double	getRows() Returns an estimate of the number of rows this relational expression will return.
boolean	isKey(ImmutableBitSet columns) Returns whether the result of this relational expression is uniquely identified by this columns with the given ordinals.

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

copy, copy, deriveRowType, explainTerms, getInputs, isHomogeneous, replaceInput

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

accept, accept, childrenAccept, collectVariablesSet, collectVariablesUsed, computeDigest, computeSelfCost, explain, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getQuery, getRelTypeName, getRowType, getTable, getTraitSet, getVariablesStopped, isDistinct, 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

Minus

public Minus(RelOptCluster cluster,
     RelTraitSet traits,
     List<RelNode> inputs,
     boolean all)

Minus

protected Minus(RelInput input)

Creates a Minus by parsing serialized output.

Method Detail

getRows

public double getRows()

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:

getRows in interface RelNode

Overrides:

getRows in class AbstractRelNode

Returns:

Estimate of the number of rows this relational expression will return

isKey

public boolean isKey(ImmutableBitSet columns)

Description copied from interface: RelNode

Returns whether the result of this relational expression is uniquely identified by this columns with the given ordinals.

For example, if this relational expression is a LogicalTableScan to T(A, B, C, D) whose key is (A, B), then isKey([0, 1]) yields true, and isKey([0]) and isKey([0, 2]) yields false.

Specified by:

isKey in interface RelNode

Overrides:

isKey in class SetOp

Parameters:

columns - Ordinals of key columns

Returns:

Whether the given columns are a key or a superset of a key