The instance ID is a two-character code that identifies a specific instance on a node and allows all processes and images to be installed and shared successfully. The value of the instance ID is stored in the II_INSTALLATION environment variable.

In the default instance name Ingres II, the instance ID is II.

The first character of an instance ID must be a letter; the second character can be a letter or numeral. The default instance ID is II.

If you have more than one instance on the same node, each instance on that node must have a unique instance ID. For example, you can install and run a new version of Actian X under one instance name, while maintaining an existing older version under a different instance name on the same computer or network node.