The present teaching relates to system, method, and programming for indexing user records. A plurality of user records are obtained, wherein each user record is associated with a user identifier and one or more data-segments. For each data-segment, one or more user identifiers associated with the data-segment are determined, a relative distance of each user identifier with respect to a previous user identifier associated with the data-segment is computed, and a variable number of bits to be used to store the relative distance of each user identifier in a bit stream are determined based on a criterion associated with the relative distance. Offset values are generated for the one or more data-segments, wherein an offset value of a data-segment indicates an index of the bit stream where information of a first user identifier associated with the data-segment is stored.