com.pervasive.datarush.matching.block

Class BlockRecords

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.CompositeOperator

com.pervasive.datarush.matching.block.BlockRecords

All Implemented Interfaces:

LogicalOperator

public class BlockRecords
extends CompositeOperator

Block records into groups of like records based on a set of key fields and generate record pairs from these groups. Blocking records in this way allows reduces the number of record pairs generated which leads to many less comparison operations. This can dramatically speed up execution of record matching if the keys are trustworthy.

The output is generated as a set of flows each containing record pairs generated from the input data source. Since the partitioning is based on key values, the output flows may be unbalanced in terms of the number of record pairs contained within each.

Constructor Summary

Constructors

Constructor and Description
BlockRecords() Generates pairs of records based on matching key fields.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	compose(CompositionContext ctx) Compose the body of this operator.
String	getLeftFieldPattern() Gets the output naming pattern for fields from the left hand input.
RecordPort	getLeftInput() Gets the record port providing the left hand input to the pair generation.
String[]	getLeftKeys() Gets the fields used as keys for data on the left hand side.
RecordPort	getOutput() Gets the record port providing the results of the pair generation.
String	getRightFieldPattern() Gets the output naming pattern for fields from the right hand input.
RecordPort	getRightInput() Gets the record port providing the right hand input to the pair generation.
String[]	getRightKeys() Gets the fields used as keys for data on the right hand side.
void	setLeftFieldPattern(String pattern) Sets the output naming pattern for fields from the left hand input.
void	setLeftKeys(String[] keys) Sets the fields used as keys for data on the left hand side.
void	setRightFieldPattern(String pattern) Sets the output naming pattern for fields from the right hand input.
void	setRightKeys(String[] keys) Sets the fields used as keys for data on the right hand side.

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

BlockRecords

public BlockRecords()

Generates pairs of records based on matching key fields. These fields must be identified before execution.

See Also:

setLeftKeys(String[]), setRightKeys(String[])

Method Detail

getLeftInput

public RecordPort getLeftInput()

Gets the record port providing the left hand input to the pair generation.

Returns:

the left input port for the operation

getRightInput

public RecordPort getRightInput()

Gets the record port providing the right hand input to the pair generation.

Returns:

the right input port for the operation

getOutput

public RecordPort getOutput()

Gets the record port providing the results of the pair generation.

Returns:

the output port for the operation

getLeftFieldPattern

public String getLeftFieldPattern()

Gets the output naming pattern for fields from the left hand input.

Returns:

the pattern for the left hand side field names in output.

setLeftFieldPattern

public void setLeftFieldPattern(String pattern)

Sets the output naming pattern for fields from the left hand input. This is used to ensure distinct names in the output pairs.

Parameters:

pattern - name pattern for the left hand side field names

getRightFieldPattern

public String getRightFieldPattern()

Gets the output naming pattern for fields from the right hand input.

Returns:

the pattern for the right hand side field names in output.

setRightFieldPattern

public void setRightFieldPattern(String pattern)

Sets the output naming pattern for fields from the right hand input. This is used to ensure distinct names in the output pairs.

Parameters:

pattern - name pattern for the right hand side field names

getLeftKeys

public String[] getLeftKeys()

Gets the fields used as keys for data on the left hand side.

Returns:

the key fields on the left hand side

setLeftKeys

public void setLeftKeys(String[] keys)

Sets the fields used as keys for data on the left hand side. There must be an equal number of keys specified on the left and right sides. Only record pairs where these keys are equal will be output; key comparison is done by position.

Parameters:

keys - the key fields on the left hand side

getRightKeys

public String[] getRightKeys()

Gets the fields used as keys for data on the right hand side.

Returns:

the key fields on the right hand side

setRightKeys

public void setRightKeys(String[] keys)

Sets the fields used as keys for data on the right hand side. There must be an equal number of keys specified on the left and right sides. Only record pairs where these keys are equal will be output; key comparison is done by position.

Parameters:

keys - the key fields on the right hand side

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