Systems and methods for efficiently obtaining a summary from and locating data in a log file allow a user to efficiently obtain summary information and locate specific data records even in large log files. The system includes a configuration program, a log writing program, and a log reading program. The configuration program allows the user to control the duration of monitoring and the frequency of summary record creation by the log writing program. The log writing program writes data records, summary records, and summary information to a log file in response to monitored events. The log reading program retrieves summary records and data records from the log file using summary information in response to user requests.