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IMS-DC Introduction


IMS is a hierarchical DBMS, supplied by IBM & runs on mainframe computers. It has 2 components.

  1. Data Base (DB) processing

  2. Data Communication (DC) processing

Major kinds of online programs that can be written:

  • Inquiry programs

  • Data Entry programs

  • Maintenance programs

  • Menu programs

Comparison between online and batch programs:

Batch SystemOnline System
Pre-determined scheduling intervals Arbitrary scheduing by users
Necessary creation of input files Processing of data as it occurs
Lack of access to current data Data up-to-date and current and available for inquiry
Delay in processing erroneous data Immediate error creation
Databases cannot be shared with other updating programs Database can be shared with other updating programs

Software components of an IMS DC system:


IMS-DC offers:

  1. A way to improve customer and interval service by providing current and consistent information

  2. A way to interact with users with critical response times

  3. A way to distribute processing function to different locations

  4. A way to improve productivity for online applications

Features of IMS

  1. Manages IMS-DC terminal network

  2. Routes messages for various destination

  3. Scheduling of messages

  4. Manages resources allocated to IMS

  5. Provides restart, recovery facilities

  6. Interacts with databases for data retrieval and updation

If you have any doubts or queries related to this chapter, get them clarified from our Mainframe experts on IBMMainframer Community!

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