The Exact module provides a finer grained but more computationally expensive alternative to the Phrase module. The Exact module groups the results into three strata, based on how well they match the query string:
The highest stratum contains results whose complete text matches the user’s query exactly.
The middle stratum contains results that contain the user’s query as a subphrase.
The lowest stratum contains other match types such as normal conjunctive matches. Any match that would not be a match without query expansion lands in the lowest stratum. Records that do not contain relevance ranking terms such as those specified in the
Nrrquery parameter are also in this stratum.
The Exact module is intended for use only on small text fields such as dimension values or small property values like part IDs. Do not use it with large or offline documents. Using this module in these cases results in poor performance or application failures due to request timeouts. The Phrase module, with and without approximation turned on, does similar but less sophisticated ranking that can be used as a better performance substitute.
