Upgrading Informix® (in-place migration)

In-place migration upgrades Informix® directly to the current version by installing the product in a new directory on the same computer, copying a few configuration files, and starting the new server to automatically convert your database data.

In-place migration uses your existing test and production hardware. The operating system on those computers must be supported by the new version of the server. Also, you must have enough space for the system database data conversion.

Upgrading consists of these steps:

1. Prepare your system. That includes closing all transactions, verifying the integrity of the data with the oncheck utility, and performing a level-0 backup. (If you are using Enterprise Replication or high-availability clusters, you must stop replication and perform required extra tasks.)

   If you remove in-place alter operations before you upgrade, you might speed up the upgrade process. Use a process similar to removing in-place alter operations during reversion.

2. UNIX: Log in to the database server as the root user or, for a non-root installation, log in as the user who owns the database server.
3. Windows: Log in to the database server as a member of the Administrator's group or, for a non-root installation, log in as the user who owns the database server.
4. Install the new product on the computer.

   Important: The safest way to upgrade to a new version is to install the new version in another directory. To save space, you can select the product components that you want to install. After you test the database server instance with the similar configuration settings and the client connection information that you use for your current database server, you can remove the old version.

   If you do not have space on your computer for two versions, install the new version over the existing version. In this case, you cannot selectively install components; you must install the whole product to block objects from the previous version. Before you choose this approach, make sure that you have the original installation media for the old version because you cannot automatically revert to it.

   Note: Ensure that the desired edition is installed.
5. Copy the appropriate configuration files, such as the onconfig file and the sqlhosts file, to the new INFORMIXDIR/etc directory. Set parameters that are new for the current release.
6. Set the INFORMIXDIR environment variable to the directory of the new installation.
7. Start an instance of the new version of Informix®. The database data is automatically converted.
8. If you notice performance problems, run UPDATE STATISTICS and UPDATE STATISTICS FOR PROCEDURE operations.

This type of migration minimizes the risk of introducing errors. You can always revert from the new server to the old one. If you have a problem during reversion, you can restore the level-0 backup.