12. A method of generating Structured Query Language (SQL) statements to alter database types in a database system that has definition data that defines a set of one or more database object types, the method comprising: receiving a first Extensible Markup Language (XML) schema; and based on said first XML schema, generating one or more SQL statements that, when executed, cause a database server to alter said set of one or more database object types; wherein said one or more database object types were generated based on a second XML schema that differs from said first XML schema.
12. A method of generating Structured Query Language (SQL) statements to alter database types in a database system that has definition data that defines a set of one or more database object types, the method comprising: receiving a first Extensible Markup Language (XML) schema; and based on said first XML schema, generating one or more SQL statements that, when executed, cause a database server to alter said set of one or more database object types; wherein said one or more database object types were generated based on a second XML schema that differs from said first XML schema. 27. A volatile or non-volatile computer-readable storage medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 12 .