org.cloudgraph.hbase.scan

Class ScanCollector

java.lang.Object

org.cloudgraph.hbase.scan.ScanCollector

All Implemented Interfaces:

ExprVisitor

public class ScanCollector
extends Object
implements ExprVisitor

Collector visitor which supports the "recognition" of one or more partial, fuzzy and other scan constructs within the context of a binary (query) expression syntax tree, encapsulating operator precedence and other factors.

Composite row key scans represent only logical binary 'AND' expressions across the key fields. So for relational binary expressions linked within a query syntax tree by one or more logical binary 'AND', expressions, a single partial or fuzzy row key scan may be used. But for relational binary expressions linked by logical binary 'OR' expressions multiple scans must be used. Clients of this collector class may execute the resulting scans in series or in parallel depending on various performance and other considerations.

Since:

0.5.3

Author:

Scott Cinnamond

See Also:

org.cloudgraph.hbase.expr.Expr, org.cloudgraph.hbase.expr.BinaryExpr, org.cloudgraph.hbase.expr.ExprVisitor, DataGraphMapping, org.cloudgraph.hbase.expr.LogicalBinaryExpr, org.cloudgraph.hbase.expr.RelationalBinaryExpr, org.cloudgraph.hbase.expr.PredicateBinaryExpr

Constructor Summary

Constructors

Constructor and Description
ScanCollector(org.plasma.sdo.PlasmaType rootType, StoreMappingContext mappingContext)

Method Summary

Modifier and Type	Method and Description
List<CompleteRowKey>	getCompleteRowKeys()
List<FuzzyRowKey>	getFuzzyRowKeyScans()
DataGraphMapping	getGraph()
List<PartialRowKey>	getPartialRowKeyScans()
boolean	isQueryRequiresGraphRecognizer()
void	visit(Expr target, Expr source, int level)

Methods inherited from class java.lang.Object

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

Constructor Detail

ScanCollector

public ScanCollector(org.plasma.sdo.PlasmaType rootType,
                     StoreMappingContext mappingContext)

Method Detail

getGraph

public DataGraphMapping getGraph()

isQueryRequiresGraphRecognizer

public boolean isQueryRequiresGraphRecognizer()

getPartialRowKeyScans

public List<PartialRowKey> getPartialRowKeyScans()

getFuzzyRowKeyScans

public List<FuzzyRowKey> getFuzzyRowKeyScans()

getCompleteRowKeys

public List<CompleteRowKey> getCompleteRowKeys()

visit

public void visit(Expr target,
                  Expr source,
                  int level)

Specified by:

visit in interface ExprVisitor