A non-transitory computer readable medium storing a program that causes a computer to execute a process, the process including obtaining text data, generating first index information indicating appearance positions in the text data for each of a plurality of characters or words obtained based on lexical analysis of the text data, generating second index information, the second index information being index information in which the appearance positions in the text data are aggregated for each character or word, specifying a data range in the first index information, to be referred in a pattern match search by using the second index information, and performing encoding for the text data based on the pattern match search by using the data range in the first index information.