IMS Universal DL/I driver interfaces for executing DL/I operations

In a traditional IMS application, you make DL/I calls to insert, update, delete, or retrieve data. To perform the same functions in a IMS Universal DL/I driver application, you invoke methods.

Methods are defined in the following interfaces:

• The program specification block (PSB) interface is used to connect to IMS databases. Use the PSB interface to obtain a handle to any program communication block (PCB) that is contained in the PSB. The PCB handle is used to access the particular database that is referenced by the PCB.
• The PCB interface represents a cursor position in an IMS database. The PCB interface supports DL/I message call functions, including Get Unique (GU), Get Next (GN), Get Next Within Parent (GNP), Insert (ISRT), Replace (REPL), and Delete (DLET). The PCB interface can obtain an unqualified list of segment search arguments and perform batch retrieve, update, and delete operations. You can also use the PCB interface to return the application interface block (AIB) that is associated with the most recent DL/I call.
• The SSAList interface represents a list of segment search arguments (SSAs) used to specify the segments to target in a particular database call. Use the SSAList interface to construct the SSAs, and to set the command codes and lock class for the SSAs. You can set an initial qualification statement and append additional qualifiers, based on the values of the segment fields, to restrict which segments to target in the DL/I call. You can also specify which fields to return from a database retrieve call.
• The Path interface represents a database record for the purpose of a DL/I retrieval or update operation. The Path interface can be viewed as the concatenation of all of the segment instances in a specific database hierarchic path, starting from the highest level segment that is nearest the root segment to the lowest level segment. Use the Path interface to set or retrieve the value of any segment field that is located in the hierarchic path.
• The PathSet interface provides access to a collection of Path objects that are returned by a batch retrieve operation.
• The AIB interface and the database PCB (DBPCB) interface return useful information that was returned by IMS as a result of a DL/I call.
• The GSAMPCB interface represents a GSAM PCB and is essentially a cursor position in a GSAM database. This interface provides data access to GSAM databases with calls that are similar to DL/I calls.
• The RSA interface represents a GSAM database record search argument that is the key to a cursor position in the GSAM database.