The Collapsing query parser and the Expand component combine to form an approach to grouping documents for field collapsing in search results. The Collapsing query parser groups documents (collapsing the result set) according to your parameters, while the Expand component provides access to documents in the collapsed group for use in results display or other…
Spell Checking – Ultimate Solr Guide
The SpellCheck component is designed to provide inline query suggestions based on other, similar, terms. The basis for these suggestions can be terms in a field in Solr, externally created text files, or fields in other Lucene indexes. Configuring the SpellCheckComponent Define Spell Check in solrconfig.xml The first step is to specify the source of…
MoreLikeThis – Ultimate Solr Guide
The MoreLikeThis search component enables users to query for documents similar to a document in their result list. It does this by using terms from the original document to find similar documents in the index. There are three ways to use MoreLikeThis. The first, and most common, is to use it as a request handler. In this…
Transforming Result Documents – Ultimate Solr Guide
Document Transformers modify the information returned about documents in the results of a query. Using Document Transformers When executing a request, a document transformer can be used by including it in the fl parameter using square brackets, for example: Some transformers allow, or require, local parameters which can be specified as key value pairs inside the brackets:…
Learning To Rank – Ultimate Solr Guide
With the Learning To Rank (or LTR for short) contrib module you can configure and run machine learned ranking models in Solr. The module also supports feature extraction inside Solr. The only thing you need to do outside Solr is train your own ranking model. Learning to Rank Concepts Re-Ranking Re-Ranking allows you to run a simple query for…
Query Re-Ranking – Ultimate Solr Guide
Query Re-Ranking allows you to run a simple query (A) for matching documents and then re-rank the top N documents using the scores from a more complex query (B). Since the more costly ranking from query B is only applied to the top N documents, it will have less impact on performance then just using the complex…
The Extended DisMax (eDismax) Query Parser – Ultimate Solr Guide
The Extended DisMax (eDisMax) query parser is an improved version of the DisMax query parser. In addition to supporting all the DisMax query parser parameters, Extended Dismax: supports Solr’s standard query parser syntax such as (non-exhaustive list): boolean operators such as AND (+, &&), OR (||), NOT (-). optionally treats lowercase “and” and “or” as “AND” and “OR”…
The DisMax Query Parser – Ultimate Solr Guide
The DisMax query parser is designed to process simple phrases (without complex syntax) entered by users and to search for individual terms across several fields using different weighting (boosts) based on the significance of each field. Additional options enable users to influence the score based on rules specific to each use case (independent of user…
The Standard Query Parser – Ultimate Solr Guide
Solr’s default Query Parser is also known as the “lucene” parser. The key advantage of the standard query parser is that it supports a robust and fairly intuitive syntax allowing you to create a variety of structured queries. The largest disadvantage is that it’s very intolerant of syntax errors, as compared with something like the DisMax query…
