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Yonik Seeley commented on SOLR-1321: ------------------------------------ I've always been in favor of just allowing leading wildcards for all fields, but I think others disagreed on that point. > Support for efficient leading wildcards search > ---------------------------------------------- > > Key: SOLR-1321 > URL: https://issues.apache.org/jira/browse/SOLR-1321 > Project: Solr > Issue Type: Improvement > Components: Analysis > Affects Versions: 1.4 > Reporter: Andrzej Bialecki > Assignee: Grant Ingersoll > Fix For: 1.4 > > Attachments: SOLR-1321.patch, wildcards-2.patch, wildcards-3.patch, > wildcards.patch > > > This patch is an implementation of the "reversed tokens" strategy for > efficient leading wildcards queries. > ReversedWildcardsTokenFilter reverses tokens and returns both the original > token (optional) and the reversed token (with positionIncrement == 0). > Reversed tokens are prepended with a marker character to avoid collisions > between legitimate tokens and the reversed tokens - e.g. "DNA" would become > "and", thus colliding with the regular term "and", but with the marker > character it becomes "\u0001and". > This TokenFilter can be added to the analyzer chain that it used during > indexing. > SolrQueryParser has been modified to detect the presence of such fields in > the current schema, and treat them in a special way. First, SolrQueryParser > examines the schema and collects a map of fields where these reversed tokens > are indexed. If there is at least one such field, it also sets > QueryParser.setAllowLeadingWildcards(true). When building a wildcard query > (in getWildcardQuery) the term text may be optionally reversed to put > wildcards further along the term text. This happens when the field uses the > reversing filter during indexing (as detected above), AND if the wildcard > characters are either at 0-th or 1-st position in the term. Otherwise the > term text is processed as before, i.e. turned into a regular wildcard query. > Unit tests are provided to test the TokenFilter and the query parsing. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.