Specifying a Database Object in a Cross-Database Query

To specify an object in another database of the local database server, you must qualify the identifier of the object with the name of the database (and of the owner, if the external database is ANSI compliant), as in this example:

corp_db:hrdirector.executives

In this example, the name of the external database is corp_db. The name of the owner of the table is hrdirector. The name of the table is executives. Here the colon ( : ) separator is required after the database qualifier.

In HCL OneDB™, queries and other data manipulation language (DML) operations on other databases of the local database server can access most of the built-in opaque data types, as listed in Data Types in Cross-Database Transactions. DML operations can also access user-defined data types (UDTs) that can be cast to built-in types, as well as DISTINCT types that are based on built-in types, if each DISTINCT types and UDT is cast explicitly to a built-in type, and if all the DISTINCT types, UDTs, and casts are defined in all of the participating databases. The same data-type restrictions also apply to the arguments and to the returned values of a user-defined routine (UDR) that accesses other databases of the local HCL OneDB instance, if the UDR is defined in all of the participating databases.