The advent of telecommunication era and the constant development of hardware and network structures have encouraged the decentralization of data while increasing the needs to access information from different sites. Query optimization strategies aim to minimize the cost of transferring data across networks. Many techniques and algorithms have been proposed to optimize queries. Perhaps one of the more important algorithms is the AHY algorithm using semi-joins that is implemented by Apers, Hevner and Yao. Nowadays, a new technique called PERF (Partially Encoded Record Filters), presented by Kenneth Ross seems to bring some improvement over semijoins. PERF joins are two-way semi-joins using a bit vector as their backward phase. Our research encompasses applying PERF joins to the AHY algorithm and producing the AHYPERF algorithm. Programs were designed to implement both the AHY and AHYPERF. Several experiments were conducted and the results showed a very considerable enhancement of AHYPERF over the original AHY.