The hierarchy of server option settings
When you have the same server option set with one value for a data source type and set with another value on a specific data source server, there is a hierarchy among the settings.
For example, the PLAN_HINTS server option is set to 'Y' for the data source type SYBASE. However, the PLAN_HINTS server option is set to 'N' in the server definition for a specific Sybase data source server PURNELL. The setting for the specific data source server overrides the setting for the data source type. This configuration causes PLAN_HINTS to be enabled at all Sybase data source servers except PURNELL.