Transaction logging

Transaction logging has been used extensively in Okapi‐related projects to allow search algorithms and user interfaces to be investigated, evaluated and compared. Logging software may be independent of the system being examined, or integrated with it. Logging is undertaken for various purposes: recovery, playback or analysis, and the methods and formats used will vary accordingly. Logging techniques have developed over time to take into account the increasing sophistication of user interfaces and the requirement for more detailed analyses of the recorded data. A series of examples is presented, illustrating logging for both character‐based and GUI systems, and demonstrating the usefulness of a relational DBMS for storing and analysing log data. Future work will involve developing logging techniques for distributed versions of Okapi.