uk.ac.ic.doc.rodex.qproc
Class QueryRewriter

java.lang.Object
  uk.ac.ic.doc.rodex.qproc.QueryRewriter

Direct Known Subclasses:

MiniConQueryRewriter, RangeBasedQueryRewriter

public abstract class QueryRewriter
extends java.lang.Object

Field Summary

protected QueryAnalyser	_qa
protected ASG	query
protected java.util.List	views

Constructor Summary

QueryRewriter()
Creates a new instance of QueryRewriter

Method Summary

abstract QueryAnalyser	analyse() Analyse query and view rules to prepare for the actual rewriting to take place
abstract QueryAnalyser	getQueryAnalyser() Return reference to the QueryAnalyser object which was used to analyse the query
static QueryRewriter	getQueryRewriterInstance(ASG query, ASG extent, int rewriterType) Special-purpose rewriters
static QueryRewriter	getQueryRewriterInstance(ASG query, java.util.List views, int rewriterType) A factory method to create a new QueryRewriter object
static QueryRewriter	getQueryRewriterInstance(ASG query, QueryAnalyser[] viewMetadata, int rewriterType) An overloading factory method to create a new QueryRewriter object given metadata objects of cached views
static QueryRewriter	getQueryRewriterInstance(QueryAnalyser qa, ASG extent, int rewriterType) Special-purpose rewriters
abstract QueryRewriterResult	rewrite() Rewrite query

Methods inherited from class java.lang.Object

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

Field Detail

query

protected ASG query

views

protected java.util.List views

_qa

protected QueryAnalyser _qa

Constructor Detail

QueryRewriter

public QueryRewriter()

Creates a new instance of QueryRewriter

Method Detail

getQueryRewriterInstance

public static QueryRewriter getQueryRewriterInstance(ASG query,
                                                     java.util.List views,
                                                     int rewriterType)

A factory method to create a new QueryRewriter object

Parameters:

rewriterType - the rewriter type which should be one of:

• #TYPE_BUCKET
• #TYPE_INVERSE_RULE
• #TYPE_MINICON

Returns:

QueryWriter a query rewriter object

getQueryRewriterInstance

public static QueryRewriter getQueryRewriterInstance(ASG query,
                                                     QueryAnalyser[] viewMetadata,
                                                     int rewriterType)

An overloading factory method to create a new QueryRewriter object given metadata objects of cached views

Parameters:

query - the query to rewrite

viewMetadata - an array of QueryAnalyser objects

rewriterType - the rewriter type which should be one of:

• #TYPE_BUCKET
• #TYPE_INVERSE_RULE
• #TYPE_MINICON

Returns:

QueryWriter a query rewriter object

getQueryRewriterInstance

public static QueryRewriter getQueryRewriterInstance(ASG query,
                                                     ASG extent,
                                                     int rewriterType)

Special-purpose rewriters

getQueryRewriterInstance

public static QueryRewriter getQueryRewriterInstance(QueryAnalyser qa,
                                                     ASG extent,
                                                     int rewriterType)

Special-purpose rewriters

analyse

public abstract QueryAnalyser analyse()
                               throws AutoMedException

Analyse query and view rules to prepare for the actual rewriting to take place

Returns:

QueryAnalysre object that contains query's metadata

Throws:

AutoMedException

rewrite

public abstract QueryRewriterResult rewrite()
                                     throws AutoMedException

Rewrite query

Throws:

AutoMedException

getQueryAnalyser

public abstract QueryAnalyser getQueryAnalyser()

Return reference to the QueryAnalyser object which was used to analyse
the query