One method involves receiving a search request that includes a date and phone number. A master index file is searched for the phone number. The master index file includes phone numbers associated with calls that occurred on the date in the search request. The master index file also includes the location of the first index record for the phone number in an index file. The index file includes an index record for each call record. Each index record includes a phone number from a call record and the location of the call record. In response to locating the phone number in the master index file, the index file is searched for each index record with the phone number. In response to locating an index record with the phone number, the call record associated with that index record is retrieved. A search result including each call record retrieved is returned.