Oracle9i Database Migration Release 1 (9.0.1) Part Number A90191-02 |
|
The information in this chapter only applies to release 8.1 and higher installations of Oracle. The term downgrading describes transforming an Oracle database into a previous release of the same version, such as transforming a database from release 8.1.7 to release 8.1.5. The term downgrading also describes transforming an Oracle database into a previous version, such as transforming a database from Oracle9i to Oracle7. This chapter describes downgrading to Oracle7 or release 8.0. If you want to downgrade to release 8.1 of Oracle, then see Chapter 13, "Downgrading to Release 8.1".
This chapter covers the following topics:
An Oracle9i database can be downgraded to a release 8.0 database. However, few downgrade paths are available, and the necessary procedures may require a great deal of time and effort. Also, it may not be possible to preserve data that uses new Oracle9i features that are not available with release 8.0.
The procedure for downgrading depends on whether the Oracle9i database contains new or changed data that must be preserved. Use the procedure that applies to your Oracle9i database:
If the Oracle9i database contains no new or changed data that must be preserved, then simply restore the complete backup of the previous release 8.0 source database and open it again. Make sure the restore includes the initialization parameters that were used in the previous release 8.0 database.
See Also:
Oracle9i User-Managed Backup and Recovery Guide for more information about restoring a backed up database. |
Any new or changed data in the Oracle9i database is lost when you use the method described in the previous paragraph. If your Oracle9i database has new or changed data that must be preserved, then use the procedure described in "Downgrading a Database That Contains New or Changed Data".
If the Oracle9i database contains new or changed data that must be preserved, then complete the following steps:
Oracle9i User-Managed Backup and Recovery Guide for more information about restoring a backed up database.
See Also:
Using Export/Import to return data to a release 8.0 database is relatively simple if only a few tables have been updated using Oracle9i. However, copying an entire database of tables can be a long and complicated task; therefore, you should decide whether you need to return to release 8.0 before you update many tables using Oracle9i.
The following alternate method is available for downgrading an Oracle9i database to release 8.0:
An Oracle9i database can be downgraded to an Oracle7 database (such as release 7.3). However, few downgrade paths are available, and the necessary procedures may require a great deal of time and effort. Also, it may not be possible to preserve data that uses new Oracle9i features that are not available with Oracle7.
Oracle does not support downgrading from Oracle9i to Oracle7 using the Oracle9i Migration utility; in other words, the Oracle9i Migration utility does not support backward migration. Oracle9i provides no other facilities specifically for downgrading.
The procedure for downgrading depends on whether the Oracle9i database contains new or changed data that must be preserved. Use the procedure that applies to your Oracle9i database:
If the Oracle9i database contains no new or changed data that must be preserved, then simply restore the complete backup of the previous Oracle7 source database and open it again. Make sure the restore includes the initialization parameters that were used in the previous Oracle7 database.
See Also:
Oracle9i User-Managed Backup and Recovery Guide for more information about restoring a backed up database. |
Any new or changed data in the Oracle9i database is lost when you use the method described in the previous paragraph. If your Oracle9i database has new or changed data that must be preserved, then use the procedure described in "Downgrading a Database That Contains New or Changed Data".
If the Oracle9i database contains new or changed data that must be preserved, then complete the procedure illustrated in Figure 15-1.
The following steps describe the procedure in more detail:
catexp7.sql
script on the Oracle9i database. This script is in the ORACLE_HOME
/rdbms/admin
directory.
Several other methods are available for sending table data from the Oracle9i database back to the Oracle7 database. These methods of returning data to Oracle7 are relatively simple if only a few tables have been updated using Oracle9i. However, copying an entire database of tables can be a long and complicated task; therefore, you should decide whether you need to return to Oracle7 before you update many tables using Oracle9i.
The following alternate methods are available for downgrading an Oracle9i database to Oracle7:
COPY
command to copy the new data from the Oracle9i database tables into the tables in the earlier Oracle7 database.
CREATE TABLE ... AS SELECT
). Select the data in the Oracle9i database table through a distributed query from the Oracle7 database using a database link.
Oracle9i SQL Reference for more information on the
See Also:
AS
clause of the CREATE TABLE
statement.
|
Copyright © 1996-2001, Oracle Corporation. All Rights Reserved. |
|