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David commented on SOLR-5027: ----------------------------- I have posted this information on Solr User: http://lucene.472066.n3.nabble.com/Error-with-CollapsingQParserPlugin-when-trying-to-use-tagging-td4098709.html > Field Collapsing PostFilter > --------------------------- > > Key: SOLR-5027 > URL: https://issues.apache.org/jira/browse/SOLR-5027 > Project: Solr > Issue Type: New Feature > Components: search > Affects Versions: 5.0 > Reporter: Joel Bernstein > Assignee: Joel Bernstein > Priority: Minor > Fix For: 4.6, 5.0 > > Attachments: SOLR-5027.patch, SOLR-5027.patch, SOLR-5027.patch, > SOLR-5027.patch, SOLR-5027.patch, SOLR-5027.patch, SOLR-5027.patch, > SOLR-5027.patch, SOLR-5027.patch > > > This ticket introduces the *CollapsingQParserPlugin* > The *CollapsingQParserPlugin* is a PostFilter that performs field collapsing. > This is a high performance alternative to standard Solr field collapsing > (with *ngroups*) when the number of distinct groups in the result set is high. > For example in one performance test, a search with 10 million full results > and 1 million collapsed groups: > Standard grouping with ngroups : 17 seconds. > CollapsingQParserPlugin: 300 milli-seconds. > Sample syntax: > Collapse based on the highest scoring document: > {code} > fq=(!collapse field=<field_name>} > {code} > Collapse based on the min value of a numeric field: > {code} > fq={!collapse field=<field_name> min=<field_name>} > {code} > Collapse based on the max value of a numeric field: > {code} > fq={!collapse field=<field_name> max=<field_name>} > {code} > Collapse with a null policy: > {code} > fq={!collapse field=<field_name> nullPolicy=<null_policy>} > {code} > There are three null policies: > ignore : removes docs with a null value in the collapse field (default). > expand : treats each doc with a null value in the collapse field as a > separate group. > collapse : collapses all docs with a null value into a single group using > either highest score, or min/max. > The CollapsingQParserPlugin also fully supports the QueryElevationComponent > *Note:* The July 16 patch also includes and ExpandComponent that expands the > collapsed groups for the current search result page. This functionality will > be moved to it's own ticket. -- This message was sent by Atlassian JIRA (v6.1#6144) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org