A storage control apparatus generates an evaluated compression dictionary from a compression dictionary. The compression dictionary includes, for each of different values included in original data of compressed data, a value and a compression code. The evaluated compression dictionary includes, for each value in the compression dictionary, a value and a compression code. The compressed data includes a compression code for each value in the original data. The storage control apparatus performs, in generation or update of the evaluated compression dictionary, condition evaluation of the value. A compression code of a value determined to correspond to the search condition in the condition evaluation is a condition satisfied code. The storage control apparatus is configured to, in the search, for a compression code in the search range of the compressed data: output, when there is an evaluation dictionary record including a condition satisfied code matching the compression code, a value in the evaluation dictionary record; and output, when there is no evaluation dictionary record including a condition satisfied code matching the compression code, a value that means inconsistency.