A storage device is disclosed. The storage device may comprise storage for input encoded data. A controller may process read requests and write requests from a host computer on the data in the storage. An in-storage compute controller may receive a predicate from the host computer to be applied to the input encoded data. A transcoder may include an index mapper to map an input dictionary to an output dictionary, with one entry in the input dictionary mapped to an entry in the output dictionary, and another entry in the input dictionary mapped to a “don't care” entry in the output dictionary.