Data Compression in Oracle

摘要

The Oracle RDBMS recently introduced an innovative compression technique for reducing the size of relational tables. By using a compression algorithm specifically designed for relational data, Oracle is able to compress data much more effectively than standard compression techniques. More significantly, unlike other compression techniques, Oracle incurs virtually no performance penalty for SQL queries accessing compressed tables. In fact, Oracle's compression may provide performance gains for queries accessing large amounts of data, as well as for certain data management operations like backup and recovery. Oracle's compression algorithm is particularly well-suited for data warehouses: environments, which contains large volumes of historical data, with heavy query workloads. Compression can enable a data warehouse to store several times more raw data without increasing the total disk storage or impacting query performance.