LuceneContribQuery.dtd: Elements - Entities - Source | Intro - Index
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<!-- - This DTD builds on the <a href="LuceneCoreQuery.dtd.html">core Lucene XML syntax</a> and adds support for features found in the "contrib" section of the Lucene project. - - CorePlusExtensionsParser.java is the Java class that encapsulates this parser behaviour. - - - The features added are: - <ul> - <li><a href="#LikeThisQuery">LikeThisQuery</a></li> - Support for querying using large amounts of example text indicative of the users' general area of interest - <li><a href="#FuzzyLikeThisQuery">FuzzyLikeThisQuery</a></li> - A style of fuzzy query which automatically looks for fuzzy variations on only the "interesting" terms - <li><a href="#BooleanFilter">BooleanFilter</a></li> - Is to Filters what core Lucene's BooleanQuery is to Queries - allows mixing of clauses using Boolean logic - <li><a href="#TermsFilter">TermsFilter</a></li> - Constructs a filter from an arbitrary set of terms (unlike <a href="#RangeFilter">RangeFilter</a> which requires a contiguous range of terms) - <li><a href="#DuplicateFilter">DuplicateFilter</a></li> - Removes duplicated documents from results where "duplicate" means documents share a value for a particular field (e.g. a primary key) - <li><a href="#BoostingQuery">BoostingQuery</a></li> - Influence score of a query's matches in a subtle way which can't be achieved using BooleanQuery - </ul> - @title Contrib Lucene ---> -<!-- @hidden include the core DTD --> -<!ENTITY % coreParserDTD SYSTEM "LuceneCoreQuery.dtd" > - - -<!-- @hidden Allow for extensions --> -<!ENTITY % extendedSpanQueries2 " " > -<!ENTITY % extendedQueries2 " " > -<!ENTITY % extendedFilters2 " " > - - -<!ENTITY % extendedQueries1 "|LikeThisQuery|BoostingQuery|FuzzyLikeThisQuery%extendedQueries2;%extendedSpanQueries2;" > -<!ENTITY % extendedFilters1 "|TermsFilter|BooleanFilter|DuplicateFilter%extendedFilters2;" > - - -%coreParserDTD; - -<!-- -Performs fuzzy matching on "significant" terms in fields. Improves on "LikeThisQuery" by allowing for fuzzy variations of supplied fields. -Improves on FuzzyQuery by rewarding all fuzzy variants of a term with the same IDF rather than default fuzzy behaviour which ranks rarer - variants (typically misspellings) more highly. This can be a useful default search mode for processing user input where the end user - is not expected to know about the standard query operators for fuzzy, boolean or phrase logic found in UserQuery - @example - <em>Search for information about the Sumitomo bank, where the end user has mis-spelt the name</em> - % - <FuzzyLikeThisQuery> - <Field fieldName="contents"> - Sumitimo bank - </Field> - </FuzzyLikeThisQuery> - % ---> -<!ELEMENT FuzzyLikeThisQuery (Field)*> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST FuzzyLikeThisQuery boost CDATA "1.0"> -<!-- Limits the total number of terms selected from the provided text plus the selected "fuzzy" variants --> -<!ATTLIST FuzzyLikeThisQuery maxNumTerms CDATA "50"> -<!-- Ignore "Term Frequency" - a boost factor which rewards multiple occurences of the same term in a document --> -<!ATTLIST FuzzyLikeThisQuery ignoreTF (true|false) "false"> -<!-- A field used in a FuzzyLikeThisQuery --> -<!ELEMENT Field (#PCDATA)> -<!-- Controls the level of similarity required for fuzzy variants where 1 is identical and 0.5 is that the variant contains - half of the original's characters in the same order. Lower values produce more results but may take longer to execute due to - additional IO required to read matching document ids--> -<!ATTLIST Field minSimilarity CDATA "0.5"> -<!-- Controls the minimum number of characters at the start of fuzzy variant words that must exactly match the original. - A value of zero will require no minimum and the search software will effectively scan ALL terms from a to z looking for variations. - This can incur high CPU overhead and a prefix length of just "1" will reduce this overhead to 1/26th of the original cost (assuming - an even distribution of letters used from the alphabet). - --> -<!ATTLIST Field prefixLength CDATA "1"> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST Field fieldName CDATA #IMPLIED> - - - -<!-- - Cherry-picks "significant" terms from the example child text and queries using these words. By only using significant (read: rare) terms the - performance cost of the query is substantially reduced and large bodies of text can be used as example content. - @example - <em>Use a block of text as an example of the type of content to be found, ignoring the "Reuters" word which - appears commonly in the index.</em> - % - <LikeThisQuery percentTermsToMatch="5" stopWords="Reuters"> - IRAQI TROOPS REPORTED PUSHING BACK IRANIANS Iraq said today its troops were pushing Iranian forces out of - positions they had initially occupied when they launched a new offensive near the southern port of - Basra early yesterday. A High Command communique said Iraqi troops had won a significant victory - and were continuing to advance. Iraq said it had foiled a three-pronged thrust some 10 km - (six miles) from Basra, but admitted the Iranians had occupied ground held by the Mohammed al-Qassem - unit, one of three divisions attacked. The communique said Iranian Revolutionary Guards were under - assault from warplanes, helicopter gunships, heavy artillery and tanks. "Our forces are continuing - their advance until they purge the last foothold" occupied by the Iranians, it said. - (Iran said its troops had killed or wounded more than 4,000 Iraqis and were stabilising their new positions.) - The Baghdad communique said Iraqi planes also destroyed oil installations at Iran's southwestern Ahvaz field - during a raid today. It denied an Iranian report that an Iraqi jet was shot down. - Iraq also reported a naval battle at the northern tip of the Gulf. Iraqi naval units and forces defending an - offshore terminal sank six Iranian out of 28 Iranian boats attempting to attack an offshore terminal, - the communique said. Reuters 3; - </LikeThisQuery> - % - --> -<!ELEMENT LikeThisQuery (#PCDATA)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST LikeThisQuery boost CDATA "1.0"> -<!-- Comma delimited list of field names --> -<!ATTLIST LikeThisQuery fieldNames CDATA #IMPLIED> -<!-- a list of stop words - analyzed to produce stop terms --> -<!ATTLIST LikeThisQuery stopWords CDATA #IMPLIED> -<!-- controls the maximum number of words shortlisted for the query. The higher the number the slower the response due to more disk reads required --> -<!ATTLIST LikeThisQuery maxQueryTerms CDATA "20"> -<!-- Controls how many times a term must appear in the example text before it is shortlisted for use in the query --> -<!ATTLIST LikeThisQuery minTermFrequency CDATA "1"> -<!-- A quality control that can be used to limit the number of results to those documents matching a certain percentage of the shortlisted query terms. - Values must be between 1 and 100--> -<!ATTLIST LikeThisQuery percentTermsToMatch CDATA "30"> - -<!-- - Requires matches on the "Query" element and optionally boosts by any matches on the "BoostQuery". - Unlike a regular BooleanQuery the boost can be less than 1 to produce a subtractive rather than additive result - on the match score. - @example <em>Find documents about banks, preferably related to mergers, and preferably not about "World bank"</em> - % - <BoostingQuery> - <Query> - <BooleanQuery fieldName="contents"> - <Clause occurs="should"> - <TermQuery>merger</TermQuery> - </Clause> - <Clause occurs="must"> - <TermQuery>bank</TermQuery> - </Clause> - </BooleanQuery> - </Query> - <BoostQuery boost="0.01"> - <UserQuery>"world bank"</UserQuery> - </BoostQuery> - </BoostingQuery> - % - ---> -<!ELEMENT BoostingQuery (Query,BoostQuery)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST BoostingQuery boost CDATA "1.0"> - -<!-- - Child element of BoostingQuery used to contain the choice of Query which is used for boosting purposes ---> -<!ELEMENT BoostQuery (%queries;)> -<!-- Optional boost for matches on this query. A boost of >0 but <1 - effectively demotes results from Query that match this BoostQuery. - --> -<!ATTLIST BoostQuery boost CDATA "1.0"> - - - -<!-- Removes duplicated documents from results where "duplicate" means documents share a value for a particular field such as a primary key - @example <em>Find the latest version of each web page that mentions "Lucene"</em> - % - <FilteredQuery> - <Query> - <TermQuery fieldName="text">lucene</TermQuery> - </Query> - <Filter> - <DuplicateFilter fieldName="url" keepMode="last"/> - </Filter> - </FilteredQuery> - % - --> -<!ELEMENT DuplicateFilter EMPTY> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST DuplicateFilter fieldName CDATA #IMPLIED> -<!-- Determines if the first or last document occurence is the one to return when presented with duplicated field values --> -<!ATTLIST DuplicateFilter keepMode (first | last) "first"> -<!-- Controls the choice of process used to produce the filter - "full" mode identifies only non-duplicate documents with the chosen field - while "fast" mode may perform faster but will also mark documents <em>without</em> the field as valid. The former approach starts by - assuming every document is a duplicate then finds the "master" documents to keep while the latter approach assumes all documents are - unique and unmarks those documents that are a copy. - --> -<!ATTLIST DuplicateFilter processingMode (full | fast) "full"> - - - - -<!-- Processes child text using a field-specific choice of Analyzer to produce a set of terms that are then used as a filter. - @example <em>Find documents talking about Lucene written on a Monday or a Friday</em> - % - <FilteredQuery> - <Query> - <TermQuery fieldName="text">lucene</TermQuery> - </Query> - <Filter> - <TermsFilter fieldName="dayOfWeek">monday friday</TermsFilter> - </Filter> - </FilteredQuery> - % - - --> -<!ELEMENT TermsFilter (#PCDATA)> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST TermsFilter fieldName CDATA #IMPLIED> -<!-- - A Filter equivalent to BooleanQuery that applies Boolean logic to Clauses containing Filters. - Unlike BooleanQuery a BooleanFilter can contain a single "mustNot" clause. - @example <em>Find documents from the first quarter of this year or last year that are not in "draft" status</em> - % - <FilteredQuery> - <Query> - <MatchAllDocsQuery/> - </Query> - <Filter> - <BooleanFilter> - <Clause occurs="should"> - <RangeFilter fieldName="date" lowerTerm="20070101" upperTerm="20070401"/> - </Clause> - <Clause occurs="should"> - <RangeFilter fieldName="date" lowerTerm="20060101" upperTerm="20060401"/> - </Clause> - <Clause occurs="mustNot"> - <TermsFilter fieldName="status">draft</TermsFilter> - </Clause> - </BooleanFilter> - </Filter> - </FilteredQuery> - % - --> -<!ELEMENT BooleanFilter (Clause)+> - --