US Patent 11327974 Field variability based TCAM splitting

A collection of rules comprising fields that may have wildcard values. The method includes defining first and second subsets of the fields, the second subset being exclusive of the first subset. Intersections of overlapping fields of the first subset are added to the first subset to form an augmented first subset. Metadata from the augmented first subset and the fields not selected for the first subset are combined to define second parts of the rules. Data items are classified by matching a search key to one of the first parts and one of the second parts of the rules.