Author: S K S

Secondary Indexing is used when we want to access a database without using the complete concatenated key or when we do not want to use the sequence primary fields. Index…

The different data manipulation methods used in IMS DL/I calls are as follows − ISRT CallGet Hold CallsREPL CallDLET Call Let us consider the following IMS database structure to understand…

The various data retrieval methods used in IMS DL/I calls are as follows − GU CallGN CallUsing Command CodesMultiple Processing Let us consider the following IMS database structure to understand…

SSA stands for Segment Search Arguments. SSA is used to identify the segment occurrence being accessed. It is an optional parameter. We can include any number of SSAs depending on…

PCB stands for Program Communication Block. PCB Mask is the second parameter used in the DL/I call. It is declared in the linkage section. Given below is the syntax of…

DL/I function is the first parameter that is used in a DL/I call. This function tells which operation is going to be performed on the IMS database by the IMS…

We include DL/I calls inside COBOL application program to communicate with IMS database. We use the following DL/I statements in COBOL program to access the database − Entry StatementGoback StatementCall…

An application program which includes DL/I calls cannot execute directly. Instead, a JCL is required to trigger the IMS DL/I batch module. The batch initialization module in IMS is DFSRRC00. The application…

IMS Control Blocks define the structure of the IMS database and a program's access to them. The following diagram shows the structure of IMS control blocks. DL/I uses the following…

IMS DB stores data at different levels. Data is retrieved and inserted by issuing DL/I calls from an application program. We will discuss about DL/I calls in detail in the…