Category: Mainframes

MDT and its usage in CICS with examples

Modified data Tag (MDT) is the most important feature in CICS programming consisting of MAPS. One who involves in CICS programming needs to know the importance of it for efficient coding. It is stored in 7th bit of a attribute byte of a screen field with either ‘0’(OFF) or ‘1’ (ON) as the values.(Every input

DB2 Group By and Order By Clauses

ORDER BY DB2 Order by clause is used to sort the result table values by the sort Key order. Here, sort key can be the column name or column number. Results can be sorted either by Ascending (ASC) or by Descending (DESC) order. ASC is the default order by clause. If you do not specify

DB2 Isolation Levels

DB2 Isolation Levels: How Isolation Levels are useful, what are the different Isolation Level types(CS, RR, RS & UR), how it controls the concurrency, What is Concurrency?,  which one is better to use among the four types? What are the advantages and disadvantages ?These are the questions we often encounter. So this topic explains these queries

DB2 Locks and Importance of Concurrency Control

What is a DB2 Lock? It is a Mechanism provided by DB2 to maintain the access to different database objects. What is Concurrency in DB2? Concurrency is a way which enables more than one application to access the same database object at the same time.  Locks and Concurrency control is the most important aspect in

cobol redefines clause with examples

This topic covers the redefines in COBOL & its usage, syntax, declaration, valid & Invalid redefines cases. In COBOL, Redefines clause is used to share the common storage area among different data items/groups thus saves the memory and helps to optimize the usage of working storage area. Useful in cases where the two variables are