Many real life applications require data that are inherently sequential. Sequential data exist in many domains such as temporal databases, execution monitors, trigger mechanisms, and list processing.

Traditional database systems did not pay special attention to sequence data, which resulted in tedious query expression and bad performance. This report summarizes recent research on supporting sequence data in DBMSs, covering issues such as data model, query language, query optimization, and storage management. The sequence database system SEQ is described.