Why we need to upgrade the database?
- If your application to use the new version of the database;
- If the database is running heavily loaded, and by adjusting the software and hardware can not have a fundamental improvement;
- If you want to replace the operating system platform;
- If you want to enhance the security of the database;
- There is a reason is the emergence of a new version of the database with new features mature;
- Or ORACLE stop technical support for older versions of the database, the upgrade to a higher version, you can continue to receive support from ORACLE, you can also take advantage of the new special version of the database, you can improve system performance, robustness, and expandable availability, etc.
To face of these problems, we can resolved those issues by upgrade the database. However, if your system is stable, no major performance bottleneck, then it is not necessary to upgrade the database, because the upgrade a production database will face a lot of risks.
Database upgrade or data migration will encounter a variety of situations, generally have the following situations:
- Under the same host conditions, low version of the database upgrade to higher version of the database.
- With the new patch-level database, you need to install the new patch.
- Replacing the system host, such as switching from windows to unix systems, databases need to be migrated.
- Cross-platform, cross-database version of the migration.
- Database upgrade from 32bit to 64bit.
- Standard Edition upgrade to the Enterprise Edition.
Develop a detailed database upgrade plan
Database upgrade operation will face a huge risk, so the development of a detailed and thorough upgrade and test plans before the database upgrade, repeated verification test with the various stages of the database upgrade is necessary, so as to ensure that all stages of the database upgrade understandable, predictable and be able to succeed. In general, the database upgrade test plan should include the following types of tests:
- Upgrade Test
- Minimize test
- Functional Test
- Integration Testing
- Performance Test
- Volume and load stress testing
- Specific Pre-Upgrade and Post-Upgrade Tests
- Develop a backup plan before the upgrade
- Repeated testing of the upgrade procedure (test the upgrade process)
- Test the upgraded database
Database Upgrade Preparation:
- Before upgrading the database must first be familiar with a variety of new features of the new database, such as: changes table space management segment, parameters, memory management, database flashback features, storage management, sql optimization improvements.
- Determine upgrade to the new version of the database upgrade path, the path to upgrade to 10gr2 serial number depends on the current database (release number), is likely not upgrade from the current version of the database to the latest version, this is the first upgrade to an intermediate version and then upgrade to the final version. For example: The current version is oracle220.127.116.11, first upgrade to oracle 10.2.0.5, then upgrade to oracle 18.104.22.168.
Discussion of the various methods database upgrade
Implement database upgrade can select a variety of methods, generally:
- Database Upgrade Assistant (database upgrade assistant),
- manually upgrade scripts, exp / imp (exdmp / imdmp) tool,
- tablespace transmission characteristics (transportable tablespace),
- table copy,
- materialized view (material ized view) technology,
Before the upgrade, first determine the upgrade path, choose the appropriate method depending on the circumstances of the upgrade, the upgrade process for the various stages of testing. For example, a database version mainly involved oracle8i, oracle9i, oracle10gr2, oracle 11gr2, oracle 12c the main operating system platform windows2003, windows 2008, windows 2012, oracle unbreakable linux, IBM AIX, HP UX etc. I use a variety of methods for various upgrades above process have done a test.