Oracle Tips by Burleson

Oracle10g Grid Computing with RAC
Chapter 8 - RAC Administration

RAC and Initialization Parameters

1. Parameters That Must Be Identical Across All Instances
    

2. Parameters That Must Be Unique Across All Instances
    

3. Multi-Valued Parameters

Identical Parameters (Across Instances)

These parameters are generally critical directives. Some are specified at the time of database creation, and some are specified (or modified) while the RAC system is running. They must always be common in order for the clustered instances to function.

Table 8.1 shows parameters that must be identical across all the instances. For example, since RAC is a single database with multiple instances, it must have a single parameter to show the maximum number of data files for the database. (For a more detailed explanation, see the Oracle Database 10g Database Reference Manual.) These parameters indicate the fact that we are dealing with a single database, even though access is through multiple instances. The parameters, which need to be common, are mostly database-level parameters.