A method and apparatus are provided to store transaction records in a retrievable form and to enable subsequent search and retrieval of stored transaction records. Transaction records are captured and then grouped according to predetermined grouping criteria such that they may be indexed to a first level and then efficiently compressed for bulk storage. In the event that records need to be retrieved subsequently, the first level index may be used to select one or more groups of records satisfying first level search criteria and, following retrieval of the selected groups from storage and de-compression, a second level index may be created to enable a more detailed record-level search for matching records in the retrieved groups. Preferably, the same indexing technique is used for both the first and second level of indexing.