Abstract: In a client/server computer environment having a fileserver running a mater database and clients supporting cache databases, inconsistent data write accesses are prevented by using a data locking technique, which locks data during the course of an up-date transaction requested by one client. This prevents access to the same data by another client. Data consistency is checked prior to the write access, by comparing a time stamp associated with a respective cache database entry and a time stamp associated with the index to the corresponding data entry in the master database. Time stamp equivalence obviates the need to access the master database or to transfer data across the client/server communications network.