Environments

The Interface operates in conjunction with FOCUS to access the IMS DBMS under two operating systems:

• The MVS operating system, specifically the TSO, MVS batch, and FOCUS Multi-Session Option (MSO) environments.
• The VM operating system and the CMS environment through the FOCUS Cross Machine Interface (XMI) for DL/I. The Cross-Machine Interface provides a means of running FOCUS under CMS while accessing IMS databases that exist under DOS/VSE or MVS on the same or separate physical machines. Channel-to-channel adapters, either virtual or real (dedicated), are used for the connection.

IMS versions 3.1 and above offer the DBCTL (Database Control) facility for connecting to IMS under MVS. The FOCUS IMS/DB Interface supports this facility and takes full advantage of its efficiency, security, and application control enhancements. Environments, contains a complete description of each environment available for accessing IMS databases with the Interface.

The Interface is compatible with all versions of IMS; however, access through DBCTL is available only with IMS versions 3.1 and above.

If you have the appropriate FOCUS Interfaces installed, FOCUS can implement joins between IMS databases and other file types such as FOCUS databases, QSAM and VSAM files, DB2 tables, MODEL 204 databases, and CA-IDMS/DB databases.