defined in ISO/IEC 9075-9 (published as part of SQL:2008). This appears like any other schema in the database according to the SQL specification while accessing data stored either in a different database or a different server instance. The import can be made either as an entire foreign schema or merely certain tables belonging to that foreign schema. While support for ISO/IEC 9075-9 bridges the gap between the two competing philosophies surrounding schemas, MySQL and Informix maintain an implicit association between databases while ISO/IEC 9075-9 requires that any such linkages be explicit in nature. See also Relational database management system (includes market share data) List of relational database management systems Comparison of object–relational database management systems Comparison of database administration tools Object database – some of which have relational (SQL/ODBC) interfaces. IBM Business System 12 – an historical RDBMS and related query language. References External links Comparison of different SQL implementations against SQL standards. Includes Oracle, Db2, Microsoft SQL Server, MySQL and PostgreSQL. (8 June 2007) The SQL92 standard DMBS comparison by SQL Workbench Relational databases Relational database management systems