com.bigdata.rdf.sparql.ast.explainhints

Interface IExplainHint

All Known Implementing Classes:

BottomUpSemanticsExplainHint, ExplainHint, JoinOrderExplainHint, UnsatisfiableMinusExplainHint

public interface IExplainHint

Hint to be interpreted by EXPLAIN, containing information to be exposed to the user. Such information could be potential performance bottlenecks identified throughout the query optimization phase, or potential problems due to SPARQL's bottom-up semantics.

Version:

$Id$

Author:

Michael Schmidt

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	IExplainHint.ExplainHintCategory Enum datatype categorizing an explain hint
static class	IExplainHint.ExplainHintSeverity Enum datatype specifing the severity of a given explain hint

Method Summary

Methods

Modifier and Type	Method and Description
IExplainHint.ExplainHintCategory	getExplainHintCategory()
String	getExplainHintDescription()
BOp	getExplainHintNode()
IExplainHint.ExplainHintSeverity	getExplainHintSeverity()
String	getExplainHintType()
String	getHelpLink()

Method Detail

getExplainHintType

String getExplainHintType()

Returns:

textual representation of the explain hint type

getExplainHintSeverity

IExplainHint.ExplainHintSeverity getExplainHintSeverity()

Returns:

severity of an explain hint

getExplainHintCategory

IExplainHint.ExplainHintCategory getExplainHintCategory()

Returns:

category of an explain hint

getExplainHintDescription

String getExplainHintDescription()

Returns:

a detailed description, representing the content of the hint

getExplainHintNode

BOp getExplainHintNode()

Returns:

the node affected by the explain node; note that we attach this node explicitly, since the node to which the hint is attached is not always the affected node, for instance if the affected node has been optimized away

getHelpLink

String getHelpLink()

Returns:

a link to an external help page.