DBMS_TDB package reports whether a database can be transported between platforms using the RMAN
CONVERT DATABASE command.
The package verifies that databases on the current host platform are of the same endian format as the destination platform, and that the state of the current database does not prevent transport of the database.
Oracle Database Backup and Recovery User's Guide regarding database transport using
175.1 DBMS_TDB Overview
In many cases, Oracle supports transporting databases between platforms which have the same endian format. However, even when the endian formats are the same, a database must undergo a conversion process to move from one platform to another. There are also preconditions required for the process of transporting a database, such as having the database to be transported open read-only.
DBMS_TDB package serves two purposes:
Confirming that Oracle supports transporting a database from a given source platform to a given target platform
Determining whether a database to be transported has been properly prepared for transport, and if not, identifying the condition that prevents database transport
The actual conversion is performed using the Recovery Manager
CONVERT DATABASE command. For a complete discussion of the requirements for transporting a database, the process of converting a database for transport across platforms, and examples of the use of the
DBMS_TDB subprograms in the conversion process, see Oracle Database Backup and Recovery User's Guide.
175.3 DBMS_TDB Constants
DBMS_TDB package defines several enumerated constants that should be used for specifying parameter values. Enumerated constants must be prefixed with the package name, for example,
DBMS_TDB package uses the constants shown in Table 175-1.
Table 175-1 DBMS_TDB Constants
Check all files when checking whether a database is ready for transport.
Skip files in offline tablespaces when checking whether a database is ready for transport.
Skip files in read-only tablespaces when checking whether a database is ready for transport.
175.4 DBMS_TDB Views
175.5 DBMS_TDB Operational Notes
The following notes apply to
The subprograms in this package are useful both in determining whether the desired cross-platform database conversion is possible, and in checking whether the database is ready for conversion. See Oracle Database Backup and Recovery User's Guide for details on the different uses of these subprograms are used in the conversion process.
The subprograms in this package return simple
FALSEresults to indicate whether database transport is possible. Use the subprograms with
ONfor informative messages about why transport is not possible.
175.6 Summary of DBMS_TDB Subprograms
This table lists the
DBMS_TDB subprograms and briefly describes them.
175.6.1 CHECK_DB Function
This function checks whether a database can be transported to a target platform. It tests whether transport is supported at all for a given source and destination platform, and whether the database is currently in the correct state for transport.
You can specify whether to skip checking parts of the database that are read-only or offline, if you do not plan to transport them.
The function is overloaded. The different functionality of each form of syntax is presented along with the definition.
DBMS_TDB.CHECK_DB ( target_platform_name IN VARCHAR2, skip_option IN NUMBER) RETURN BOOLEAN; DBMS_TDB.CHECK_DB ( target_platform_name IN VARCHAR2) RETURN BOOLEAN; DBMS_TDB.CHECK_DB RETURN BOOLEAN;
Table 175-3 CHECK_DB Function Parameters
The name of the destination platform, as it appears in
Specifies which, if any, parts of the database to skip when checking whether the database can be transported. Supported values are listed in Table 175-1.
If the database cannot be transported to the target platform or is not ready to be transported, returns
FALSE. If the database is ready for transport, returns
ON, then the output will contain the reasons why the database cannot be transported and how to fix the problems. For details on possible reasons and fixes, see Table 175-4.
Table 175-4 Reasons for CHECK_DB Function to Return FALSE
Unrecognized target platform name.
V$DB_TRANSPORTABLE_PLATFORMfor recognized platform names.
Target platform has a different endian format.
Conversion is not supported.
Database is not open read-only.
Open database read-only and retry.
There are active or in-doubt transactions in the database.
Open the database read-write. After the active transactions are rolled back, open the database read-only and retry the operation.
This situation can occur if users flash back the database and open it read only. The active transactions will be rolled back when the database is opened read-write.
Deferred transaction rollback needs to be done.
Open the database read-write and bring online the necessary tablespaces. Once the deferred transaction rollback is complete, open the database read-only and retry the operation.
Database compatibility version is below 10.0.0.
COMPATIBLEinitialization parameter to 10.0.0 or higher, open the database read-only, and retry the operation.
Some tablespaces have not been open read-write with compatibility version is 10.0.0 or higher.
COMPATIBLEinitialization parameter to 10.0.0 or higher, then open the affected tablespaces read-write. Shut down the database, open it read-only, and retry the operation.
This example illustrates the use of
CHECK_DB with a database that is open read-write:
SQL> SET SERVEROUTPUT ON SQL> DECLARE db_ready BOOLEAN; BEGIN db_ready := DBMS_TDB.CHECK_DB('Microsoft Windows IA (32-bit)'); END; / Database is not open READ ONLY. Please open database READ ONLY and retry. PL/SQL procedure successfully completed.
175.6.2 CHECK_EXTERNAL Function
This function determines whether a database has external tables, directories, or BFILEs.
DBMS_TDB.CHECK_EXTERNAL RETURN BOOLEAN;
If the database has external tables, directories, or BFILEs, return
TRUE. Otherwise, return
ON, then the function will output the names of the external tables, directories, and BFILEs in the database.
The database must be open read-write.
This example illustrates the use of
CHECK_EXTERNAL with a database that has several external tables, directories, and BFILEs:
SQL> SET SERVEROUTPUT ON SQL> DECLARE external BOOLEAN; BEGIN external := DBMS_TDB.CHECK_EXTERNAL; END; / The following external tables exist in the database: SH.SALES_TRANSACTIONS_EXT The following directories exist in the database: SYS.MEDIA_DIR, SYS.DATA_FILE_DIR, SYS.LOG_FILE_DIR, SYS.DATA_PUMP_DIR The following BFILEs exist in the database: PM.PRINT_MEDIA PL/SQL procedure successfully completed.