Learn Mainframe (Offline)

CICS，JCL，VSAM，DB2，IMS DB和COBOL

List of Topics

CICS

CICS is a DB/DC system which is used in online applications. CICS was developed because batch operating system can execute only batch programs. CICS programs can be written in COBOL, C, C++, Java, etc. These days, users want information within seconds and in real time.

COBOL

COBOL is a high-level language. One must understand the way COBOL works. Computers only understand machine code, a binary stream of 0s and 1s. COBOL code must be converted into machine code using a compiler.

DB2

DB2 is a database product from IBM. It is a Relational Database Management System (RDBMS). DB2 is designed to store, analyze and retrieve the data efficiently. DB2 product is extended with the support of Object-Oriented features and non-relational structures with XML.

IMS DB

Database is a collection of correlated data items. These data items are organized and stored in a manner to provide fast and easy access. IMS database is a hierarchical database where data is stored at different levels and each entity is dependent on higher level entities.

JCL

JCL is used in a mainframe environment to act as a communication between a program (Example: COBOL, Assembler or PL/I) and the operating system. In a mainframe environment, programs can be executed in batch and online mode.

VSAM

VSAM is high performance access method and data set organization, which organizes and maintains data via a catalog structure. It utilizes virtual storage concept and can protect datasets at various levels by giving passwords