Record filters are specified with query-based or file-based expressions.

Record filters can be specified directly within an MDEX Engine query. For example, the complete Boolean expression representing the desired record subset can be passed directly in an application URL.

In some cases, however, filter expressions require persistence (in the case where the application allows the end user to define and save custom part lists) or may grow too large to be passed conveniently as part of the query (in the case where a filter list containing thousands of part numbers). To handle cases such as these, the MDEX Engine also supports file-based filter expressions.

File-based filter expressions are simply files stored in a defined location containing XML representations of filter expressions. This section describes both the MDEX Engine query and XML syntaxes for filter expressions.