Mainbase number

When defining distributes databases, the mainbase number allows allocating a specific mainbase for storing instances created in the context of this collection. The main base number makes sense only for owning collections.

The mainbase number is set automatically, when allocating a main base to the extent.

Mainbase numbers should not be defined together with the cluster option, since in this case, the cluster creating instance determines the mainbase for storing data.

The mainbase number determines the mainbase for storing indexes for the collection. Instances owned by the extent are stored in the defined mainbase, too. Indexes and instances owned by other instances are stored in the same mainbase as the owning instance, i.e. in the mainbase of the owning extent. Since the owner hierarchy is unique, the mainbase for an instance can always be obtained from the schema definition.