Predicate Expressions

Predicate expressions are used in two contexts: to filter records from a database while doing a search or to generate scores when evaluating the match strength of a record. For example, if each record has a field which contains a date, and you only want to search records with dates after a certain point in time, you could use a predicate expression to select these records.

Two methods are available for defining predicate expressions: through the use of an LPAR list or, starting with the 4.0 release of the TIBCO Patterns servers, via the use of an SQL like string format. The LPAR list format is described first.