Question { IBM, 5960 }

WHAT IS NULL INDICATOR ? WERE IS THIS USED? AND IF IT IS
USED IN FILES CONCEPT? HOW DO WE USE IT?

Answer

NULL indicator specifically used to find the value is present
or not in Table. For PRIMARY key the value should present.
When working with this key in program, there may be chance of
no value is present/value truncated. In such cases, NULL
indicator is used.

In file NULL indicator cannot be used.

Question { Cognizant, 27549 }

Suppose I have 5 dataset listed under a single DD name in a
catlogued PROC. How can I override one of those 5 dataset
(say 3rd dataset)?

Answer

In the catalogued PROC, the 3rd dataset can be overridden
like below.
ORIGINAL CODE IN CATALOGUED PROC:
*********************************
//S01 DD DSN=A.B.C.D1,DISP=SHR
// DD DSN=A.B.C.D2,DISP=SHR
// DD DSN=A.B.C.D3,DISP=SHR
// DD DSN=A.B.C.D4,DISP=SHR
// DD DSN=A.B.C.D5,DISP=SHR
//
...

OVERRIDDING 3RD CONCATENATED DATASET IN CATALOGUED PROC:
******************************
//PRCN.S01 DD
// DD
// DD DSN=A3.B3.C3.D3,DISP=SHR
// DD
// DD
//
...

Question { 7136 }

How to select the duplicate rows from a table?

Answer

Select FIELD1 From As Temp Group By FIELD1 Having
Count(*) >1;

Is This Answer Correct ?

14 Yes

1 No