The Com-plete/DB2 interface uses the Resource Recovery Services attachment facility (RRSAF) of DB2. Since RRSAF, differently from CAF, allows the running of more than one DB2 connection per TCB, allocation of a separate task group with one TCB per user is no longer necessary.
All DB2 related processing for a given user runs under control of the same TCB as his application (usually, Natural).
The DB2 load-library (DSNLOAD) must be concatenated to the COMPLIB load library chain, because all relevant modules will be loaded dynamically.
During startup, Com-plete attempts to connect to DB2 using an RRSAF IDENTIFY call. If the DB2 subsystem does not accept connections, Com-plete waits for a notification from DB2 and connects when this notification arrives. When DB2 notifies Com-plete about DB2 termination, Com-plete terminates all users’ DB2 sessions, issues a TERMINATE IDENTIFY call for the master (or “watchdog”) connection, and waits for a reconnect notification from DB2.
The DB2 interface is initialized using the following SYSPARM definitions:
SERVER=(DB2,TLINDB2,ssid,plan)
where:
| ssid | The DB2 subsystem ID for the RRSAF IDENTIFY call. |
| plan | The default plan name if the application does not use an explicit open. |
Com-plete provides the following information to DB2 on the IDENTIFY and SIGNON calls for each user/application:
| Identifier (DB2 terminology) | Value (Com-plete terminology) |
|---|---|
| accounting-token | Accounting information for the user as defined in UUTIL UM. |
| user | User ID |
| application | Program name (8 bytes) + Task group name (8 bytes) + Thread group name (8 bytes) |
| workstation | LU name (TIB name) |
Software AG recommends that Natural be used for programming DB2 applications. DB2 services for the application are provided via a standard RRSAF function call to the following DB2 modules:
DSNRLI DSNWLIR DSNHLIR
The user application can supply a DB2 plan name by issuing an OPEN call providing the plan name to be used. If no explicit OPEN is received prior to an SQL call, the Com-plete/DB2 interface will issue implicit IDENTIFY, SIGNON, and CREATE_THREAD calls, with the plan name specified in the SERVER sysparm definition.
The following operator commands can be used to operate the DB2 server without having to restart Complete:
| SERV INIT DB2 TLINDB2 ssid plan | Starts the Com-plete/DB2 interface the way the SERVER statement described above would. |
| SERV TERM DB2 | Terminates the Com-plete/DB2 interface the way it terminates during Com-plete shutdown. |
| SERV DB2 DISC | Terminates all users’ DB2 sessions and issues a TERMINATE IDENTIFY call for the watchdog connection, but does not delete DB2 modules or reset statistics. |
| SERV DB2 CONN | After a SERV DB2 DISC: Issues an IDENTIFY for the watchdog connection, and allows users to use DB2 again. |