A method is disclosed for recording a text index wherein the text index comprises a plurality of data key fields. Each data key field includes a data key identifier, document identifier data, and an offset field. The document identifier data is provided to identify each document in which the data key identifier appears. The offset field includes a plurality of offset sequences wherein each offset sequence is associated with a respective document identified by the document identifier data and wherein each offset sequence identifies the location of each data key within its associated document by identifying the offset of the data key from the preceding data key. In accordance with the subject invention, the document identifier data and the offset data field are compressed by disclosed methods.