A session is the period of time between the activation of the DBH (i.e. a session start) and its normal termination (session end). During the session, there may be an interrupt (session abort), in which case the “session restart” is regarded as a continuation of a session.
The databases which are attached to a DBH in the course of a session form a DB configuration.
The DB configuration for the session is defined either with DBH load parameters (see chapter “DBH load parameters”) or, after the DBH has been started, with Database Administrator Language commands(see section “The Database Administrator Language DAL”).
A DB configuration consisting of several databases is referred to as a multi-DB configuration; a configuration consisting of one database only is referred to as a mono-DB configuration.
During a session with the independent DBH it is possible to use DAL commands to change the DB configuration, i.e. databases can be attached or detached, whether or not they are consistent. If an inconsistent database is attached it is made consistent by means of a warm start.
Altering the DB configuration after a session abort is known as reconfiguration (see "Reconfiguration" in chapter "Defining and altering the DB configuration" and section “Error types and their recovery”).