uk.org.ogsadai.dqp.lqp
Interface ScanOperator

All Superinterfaces:

Annotatable, Operator

All Known Implementing Classes:

FilteredTableScanOperator, ScanRelFunctionOperator, TableScanOperator

public interface ScanOperator
extends Operator

Interface that needs to implemented by tuple producing SCAN operators.

Author:

The OGSA-DAI Project Team.

Method Summary

DataNode	getDataNode() Returns the data node of a scan operator.
java.util.List<DataNode>	getDataNodes() Returns a list of data nodes on which a scan can be executed.
void	setDataDictionary(DataDictionary dataDictionary) Sets data dictionary.

Methods inherited from interface uk.org.ogsadai.dqp.lqp.Operator

accept, disconnect, getChild, getChildCount, getHeading, getID, getParent, getResultCardinality, getUsedAttributes, isBinary, isPartitionLeaf, renameUsedAttributes, replaceChild, setChild, setParent, update, validate

Methods inherited from interface uk.org.ogsadai.dqp.lqp.Annotatable

addAnnotation, getAnnotation, getAnnotations, removeAnnotation

Method Detail

setDataDictionary

void setDataDictionary(DataDictionary dataDictionary)

Sets data dictionary.

Parameters:

dataDictionary - data dictionary

getDataNode

DataNode getDataNode()

Returns the data node of a scan operator. If a data.node->DataNode annotation is present - a matching data node will be returned. If evaluation.node->EvaluationNode annotation is present - a first matching data node will be returned. If none of the above is defined the first data node from the call to getDataNodes() will be returned.

Returns:

data node

getDataNodes

java.util.List<DataNode> getDataNodes()

Returns a list of data nodes on which a scan can be executed. If there is more than one data node in the list it indicates that data replicas exist.

Returns:

list of data nodes