The starting and termination of the DBH and the monitoring of the current DBH session are the responsibility of the SESAM/SQL system administrator. A DBH session is the period between the starting of the DBH and its normal termination.
System administrators assign the databases to the DBH by means of entries in SQL database catalog lists or CALL DML table catalog lists (see the “Database Operation” manual). The DBH can access these databases in the course of the session.
There are three means of registering the required databases:
by means of DBH start statements
by means of the administration statements ADD-SQL-DB-CATALOG-ENTRY and ADD-OLD-TABLE-CATALOG-ENTRY during the current session (see the “Database Operation” manual)
by means of the utility statement CREATE CATALOG during the current session; this statement is used to enter newly defined databases (see the “SQL Reference Manual Part 2: Utilities” manual).
When starting the DBH, the system administrator can parameterize it by specifying DBH options. The system administrator can adapt resources, limit values, and work rules to the requirements of the current DBH session.
The SESAM/SQL system administrator can also have important information of the DBH session transferred automatically by email, see section “Sending important information of the DBH session by email”.
If necessary, system administrators can intervene in the current DBH session to control operations with the aid of administration statements and adapt the settings of the DBH options to changed conditions. The current DBH options can be saved in a file and used for the next DBH session.
The DBH administration commands RECONFIGURE-DBH-SESSION and RELOAD-DBH-SESSION are available to the SESAM/SQL system administrator for increasing the availability of the independent DBH, for importing a correction version while DBH operation is in progress, and for dynamic reconfiguration of the DBH session (see the “Database Operation” manual).
Both administration statements are executed without interrupting the DBH session. From the user viewpoint no DBH failure occurs.