This overview describes how to plan upgrading or migrating to the latest release of IBM® Informix® Dynamic Server (IDS), and the resources that you can use to assist you. Careful planning will ensure minimal impact on your business.
There are basically three ways to upgrade or migrate to the current version of IDS:
Upgrade (In-place migration)
Upgrading is a special case of migration that uses your existing hardware and operating system. You install a new or improved version of the product on the same computer, typically in a different location from your current version You then copy your configuration file and add new parameters. When you start the new IDS instance, the database data is automatically converted. For example, you can upgrade directly to IDS 11.50 from the following IDS versions: 10.00, 9.40, 9.30, 9.21 and 7.31. (To upgrade from earlier versions you must first upgrade to an interim version. See the product documentation for details.)
Migrate your environment (Non-in-place migration)
The process of "switching over” your environment from one computer to another that is on a different operating system or hardware configuration. This type of migration requires more planning and setup time compared to upgrading on your existing computer. In this case, the two versions of IDS differ in various ways: different architecture, page size, optimization of dbspaces, and extent allocations. You must modify and copy the database schema, user data, and user objects from one server to another server.
Migrate from a non-IBM database
The process of moving your data from another database management system (DBMS) such as Oracle or Sybase SQL Anywhere to IDS. This type of migration is especially useful if you are currently using various products. You can consolidate to take advantage of the IDS features and total cost of ownership.
Depending on your environment, the process may take a few hours or several weeks. The effort is determined by many factors:
- Your current version of IDS. The older the version, the greater the effort.
- The site architecture and configuration, before and after migration.
- The level of site customization, before and after migration.
- Integration of additional software products.
- To some extent, the size of the database.
Your team needs the following skills:
- Database administration skills, to help migrate custom database extensions.
- System administration skills, to perform various system tasks: operating system installation, configuration and maintenance, installation and configuration of IDS and any additional software products.
- Application programming skills, to create and maintain scripts to evaluate and modify application programs.
You will need to complete these planning tasks:
1. Inventory the existing IDS environment assets, such as: Machines, instances, databases, database customization, custom code, IBM software, and third-party software.
2. Itemize the requirements for the post-migrated environment. New requirements can include: upgrading or adding hardware, using new features, or replacing custom-code with new built-in function.
3. Plan the upgrade or migration activities. Typical activities include:
- Performing a level-0 backup of the database.
- Shutting down the database server and preventing connections to the database until migration completes.
Important: Any connection attempts (for example, from cron jobs or monitoring scripts) to the database after you shut down the database server and during migration will cause migration to fail.
- Installing IDS Version 11.5.
- Migrating database data.
- Reverting to the previous version.
- Migrating applications before using them with the new database server.
You can choose from various tools, depending on the task that you must perform.
For in-place upgrades:
You do not use any tools. Simply initialize the server by using the
oninit utility. The data from the source database server is converted to the target database server automatically.
You can use distributed queries to move your data, or you can pick from a number of data transfer tools and utilities, such as:
– dbexport and dbimport
– onload and onunload
– dbload and dbunload
– High Performance Loader (HPL)
Each of these tools and utilities has specific advantages and limitations. Consider all of the variables and pick a tool or utility that is appropriate for your situation.
To migrate from a variety of source databases to IDS, regardless of platform, download the free, easy-to-use IBM Migration Toolkit. You can also use the HPL to move your data from non-IBM products to IDS.