com.pervasive.datarush.operators.join

Class AbstractRelationalJoin

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.CompositeOperator

com.pervasive.datarush.operators.join.AbstractRelationalJoin

All Implemented Interfaces:

LogicalOperator

Direct Known Subclasses:

FilterExistingRows, Join, SemiJoin

public abstract class AbstractRelationalJoin
extends CompositeOperator

Common base class for the various types of join that we support.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractRelationalJoin()

Method Summary

Modifier and Type	Method and Description
protected void	compose(CompositionContext ctx) Compose the body of this operator.
protected abstract RecordPort	composeJoin(CompositionContext ctx, RecordPort left, RecordPort right, JoinKey[] keys)
ScalarValuedFunction	getJoinCondition() If non-null, the condition is evaluated for every possible matching row.
JoinKey[]	getJoinKeys() Returns the join keys to use when performing the join.
RecordPort	getLeft() Returns the left input port.
RecordPort	getOutput() Returns the output port.
RecordPort	getRight() Returns the right input port.
boolean	getUseHashJoinHint() Returns whether to perform the join as a hash join.
protected int	newJoinID()
void	setJoinCondition(ScalarValuedFunction joinCondition) Sets the join condition.
void	setJoinCondition(String joinCondition) Sets the join condition.
void	setJoinKeys(JoinKey[] joinKeys) Sets the join keys to use when performing the join.
void	setJoinKeys(List<JoinKey> joinKeys) Sets the join keys to use when performing the join.
void	setJoinKeys(String[] keyFieldNames) Sets the join keys to use when performing the join.
void	setJoinKeys(String[] leftKeyFieldNames, String[] rightKeyFieldNames) Sets the join keys to use when performing the join.
void	setUseHashJoinHint(boolean useHashJoinHint) Sets whether to perform the join as a hash join.

Methods inherited from class com.pervasive.datarush.operators.AbstractLogicalOperator

disableParallelism, getInputPorts, getOutputPorts, newInput, newInput, newOutput, newRecordInput, newRecordInput, newRecordOutput, notifyError

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractRelationalJoin

protected AbstractRelationalJoin()

Method Detail

getLeft

public RecordPort getLeft()

Returns the left input port.

Returns:

the left input port.

getRight

public RecordPort getRight()

Returns the right input port.

Returns:

the right input port

getOutput

public RecordPort getOutput()

Returns the output port. This will output the joined data.

Returns:

the output port.

getJoinCondition

public final ScalarValuedFunction getJoinCondition()

If non-null, the condition is evaluated for every possible matching row. Only those rows for which the keys match and the condition returns true will be output as an inner join. When determining the set of rows to output for an outer join, we output the set for which the join condition never evaluated to true. Note that, if specified, the left fields and right fields must be distinct from each other. This is because the function will be evaluated in a namespace containing all fields from the left and right.

Returns:

the join condition

setJoinCondition

public final void setJoinCondition(ScalarValuedFunction joinCondition)

Sets the join condition. If non-null, the condition is evaluated for every possible matching row. Only those rows for which the keys match and the condition returns true will be output as an inner join. When determining the set of rows to output for an outer join, we output the set for which the join condition never evaluated to true. Note that, if specified, the left fields and right fields must be distinct from each other. This is because the function will be evaluated in a namespace containing all fields from the left and right.

Parameters:

joinCondition - the join condition

setJoinCondition

public final void setJoinCondition(String joinCondition)

Sets the join condition. If non-null, the condition is evaluated for every possible matching row. Only those rows for which the keys match and the condition returns true will be output as an inner join. When determining the set of rows to output for an outer join, we output the set for which the join condition never evaluated to true. Note that, if specified, the left fields and right fields must be distinct from each other. This is because the function will be evaluated in a namespace containing all fields from the left and right.

Parameters:

joinCondition - a predicate expression in SQL-like syntax parsed into the join condition

getUseHashJoinHint

public final boolean getUseHashJoinHint()

Returns whether to perform the join as a hash join. If so, all rows on the right side will be loaded into into memory and joined with the left. This is an optimization for the case where the right side is small enough to fit into memory since it implies that the left side need not be sorted or repartitioned.

Returns:

whether to perform the join as a hash join

setUseHashJoinHint

public final void setUseHashJoinHint(boolean useHashJoinHint)

Sets whether to perform the join as a hash join. If so, all rows on the right side will be loaded into into memory and joined with the left. This is an optimization for the case where the right side is small enough to fit into memory since it implies that the left side need not be sorted or repartitioned.

Parameters:

useHashJoinHint - whether to perform the join as a hash join

getJoinKeys

public final JoinKey[] getJoinKeys()

Returns the join keys to use when performing the join.

Returns:

the join keys to use when performing the join.

setJoinKeys

public final void setJoinKeys(JoinKey[] joinKeys)

Sets the join keys to use when performing the join.

Parameters:

joinKeys - the join keys to use when performing the join.

setJoinKeys

public final void setJoinKeys(String[] keyFieldNames)

Sets the join keys to use when performing the join.

Parameters:

keyFieldNames - the join keys to use when performing the join.

setJoinKeys

public final void setJoinKeys(List<JoinKey> joinKeys)

Sets the join keys to use when performing the join.

Parameters:

joinKeys - the join keys to use when performing the join.

setJoinKeys

public final void setJoinKeys(String[] leftKeyFieldNames,
                              String[] rightKeyFieldNames)

Sets the join keys to use when performing the join.

Parameters:

leftKeyFieldNames - the left join keys to use when performing the join.

rightKeyFieldNames - the right join keys to use when performing the join.

newJoinID

protected final int newJoinID()

composeJoin

protected abstract RecordPort composeJoin(CompositionContext ctx,
                                          RecordPort left,
                                          RecordPort right,
                                          JoinKey[] keys)

compose

protected void compose(CompositionContext ctx)

Description copied from class: CompositeOperator

Compose the body of this operator. Implementations should do the following:

1. Perform any validation of configuration, input types, etc
2. Instantiate and configure sub-operators, adding them to the provided context via the method OperatorComposable.add(O)
3. Create necessary connections via the method OperatorComposable.connect(P, P). This includes connections from the composite's input ports to sub-operators, connections between sub-operators, and connections from sub-operators output ports to the composite's output ports

Specified by:

compose in class CompositeOperator

Parameters:

ctx - the context