CA ADS Runtime System › CA ADS Tasks, Run Units, and Transactions › Run units and database access

Run units and database access

During the execution of a CA ADS application, the following sequence occurs when accessing the database:

1. The run unit begins and READY commands are automatically issued when the CA ADS runtime system encounters the first database or logical record command that accesses database records.
2. When READY commands are physically coded in process modules, the following considerations apply:
   • The parameters from the last physically coded READY command for an area are used by the runtime system.
   • If no READY command appears in the process code, the default parameters, as defined in the subschema, are used by the runtime system.
3. The run unit that is not extended ends when the CA ADS runtime system encounters any control command except RETURN in a nested structure.

   Before executing the control command, CA ADS does the following:

   • Saves currencies unless additional specifications (NOSAVE, NOFINISH) indicate otherwise
   • Issues a FINISH command to release the database areas and write a checkpoint to the CA IDMS/DB journal

Finishing SQL Transactions

An SQL transaction is finished only when the user explicitly terminates it (using the appropriate SQL commands), or when CA ADS is terminating the task (such as DISPLAY or LEAVE ADS). A network run unit can be closed and re-opened because of a change of subschema causing CA ADS not to extend a run unit. If CA ADS has to finish such a run unit, it does not finish the SQL transaction.