Migrating Using Export/Import
This chapter provides information about using Export/Import to migrate a database from version 7 to version 8.
The following topics are covered in this chapter:
Basics of Export/Import
To migrate a database using Export/Import, complete the following three basic steps:
- Export the data from the database you are migrating (the source database). The export physically copies the data to the export dump file.
- Create the version 8 database into which you will import the exported data (the target database).
- Import the exported data into the new version 8 target database.
To migrate or upgrade a database, use the Export Utility shipped with the version or release of the source database. After the export, the Import Utility can copy the data from the export dump file into the target database. The target database must be created and operational before the Import Utility can migrate the exported data into the target database.
To migrate, upgrade, or downgrade a database, use the Import Utility shipped with the version or release of the target database.
Additional Export/Import Information Sources
If you plan to migrate a database by using Export/Import, first study Oracle8 Utilities for detailed information about using the Export/Import utilities.
Refer to the following sources if you have additional options installed.
The Trusted Oracle7 Administrator's Guide for information about migrating the features of the trusted Oracle database if you are exporting from, or importing to, a Trusted Oracle database (version 7).
Oracle8 Replication, Appendix B, "Migration and Compatibility", if you are migrating a pre-version 8 database system that has Advanced Replication installed
Migrate the Pre-Version 8 Source Database Using Export/Import
If the source Oracle database is earlier than Version 6, first upgrade the source database to at least version 6 before proceeding with export.
To migrate an Oracle database using the Export/Import utilities, complete the following steps:
- Export the source database using the Export Utility shipped with the source database. See the source database's server Utilities documents for information about using the Export Utility on the source database. Both version 7 and version 6 database exports can be imported into version 8.
To ensure a consistent export, make sure the source database is not available for updates during and after the export. If the source database will be available to users for updates after the export, then, prior to making the source database available, put procedures in place to copy the changes made in the source database to the version 8 target database after the import is complete.
- Install the version 8 software. Installation steps for version 8 are specific to your platform, as detailed in your platform-specific version 8 documentation and in the README file included with version 8.
- If the new version 8 database will have the same name as the existing source database, shut down the existing database before creating the new version 8 database.
- Create the version 8 target database.
- Open the new version 8 target database by entering the following commands from Server Manager:
SVRMGR> CONNECT INTERNAL
- Pre-create tablespaces, users, and tables in the target database to improve space usage by changing storage parameters. When you pre-create tables using SQL*Plus or Server Manager, either run the database in the original database compatibility mode or make allowances for the specific data definition conversions that occur during import.
If the new version 8 database will be created on the same machine as the source database, and you do not want to overwrite the source database datafiles, you must pre-create the tablespaces and specify IGNORE=Y and DESTROY=N when you import.
- Use the version 8 Import Utility to import the objects exported from the source database. Include the LOG parameter to save the informational and error messages from the import session to a file.
- After the migration, check the import log file for information about which import(s) of which object(s) completed successfully and which failed.
Oracle8 Utilities and the version 8 server README file for error handling information.
- Use further Import scenarios (see Oracle8 Utilities) or SQL scripts used to create the source objects to clean up incomplete imports (or possibly to start an entirely new import).
- If changes are made to the source database after the export (Step 1 ), make sure those changes are propagated to the version 8 database prior to making it available to users.
- Complete the procedures described in Chapter 5, "After Migrating the Database".