IBM MainFrame Interview Questions And Answers

//STEP1 EXEC PGM=SORT
//SYSPRINT DD SYSOUT=*
//SYSOUT DD SYSOUT=*
//SORTIN DD DSN=INPUT.DATA,DISP=SHR
//OUTDATA DD DSN=OUTPUT.DATA,DISP=(NEW,CATLG,DELETE)
.
.
.
//SYSIN DD *
OPTION COPY
OUTFIL FNAMES=OUTDATA,SAMPLE=2

THIS WILL COPY ALL EVEN RECORDS
-------------------------------------------
FOR ODD RECORDS
OUTFIL FNAMES=OUTDATA,STARTREC=1,SAMPLE=2

First need to sort both files
READ FILE1
READ FILE2
PERFORM UNTIL EOF = 'Y'
IF FILE1-ID > FILE2-ID THEN
READ FILE2 AT END MOVE 'Y' TO EOF
ELSE IF FILE1-ID < FILE2-ID
READ FILE1 AT END MOVE 'Y' TO EOF
ELSE IF FILE1-ID = FILE2-ID
WRITE FILE3
READ FILE1 AT END MOVE 'Y' TO EOF
READ FILE2 AT END MOVE 'Y' TO EOF
END-PERFORM

Linkage section is used to accept data from outside the program.either its parm part of Jcl or Call from any other programs,they pass data into called program thru linkage section only.

Comp is binary.its the type how system stores ur data.
pic s9(1)-->pics9(4) --occupies 2bytes
pic s9(5)---pic s9(8) ----4 bytes
pic s9(9)---pics9(18)-----8 bytes

comp-3 is for packed decimal data where each character occupies half byte and sign is stored in last nibble.

In IBM Cobol

1) In IBM's Language Environment you can dynamically
acquire storage (look up HEAP in the manual). The storage
you acquire you can use as you like. Can be an array,
therefore a dynamic array. It is a "work-around" as dynamic
arrays are not directly supported.
2) 01 SINGLE-DIM-ARRAY
05 SDA-ITEM PIC X OCCURS 30.
A single-dimension array of thirty one-byte characters.
3) 01 MULTI-DIM-ARRAY.
05 MDA-FIRST-DIM OCCURS 20.
07 MDA-SECOND-DIM OCCURS 30 PIC X.
A multi-dimension array of 20 times 30 one-byte characters.

Move highvalues to the key of the VSAM file and the issue Readnext record command. Then give Readprev command. This will read the last record. In VSAM, there is one command HURBA, Using that we can read the last record, If you want to know more about go to IBM RED BOOKS. You will get the solution.
by using the HURBA we can get the max records by using the CKD count key data we will get the last record

By using DFSORT we can eliminate the duplicates

//Sysin dd *
sort fields=(1,5,ch,A)
sum fields=
/*
//
in the above dfsort we use sum fields= empty then it
eliminate the duplicates

if u want all dupli.in one file u can use
sum fields = xsum........

File-aid tool is online tool (application) used for
processing files using online screens. File-aid utility is
used in jcl for processing files in batch.

//PROC1 PROC
//STEP1 EXEC PGM=IEFBR14
//DD1 DD DSN=XYZ, DISP=SHR
//SYSPRINT DD SYSOUT=*
//SYSIN DD DUMMY
// PEND


//JJJ JCLLIB ORDER=PROCLIB PATH
//PROC2 PROC
//STEP2 EXEC PROC1


//JOBNAME JOB PARAMETERS
//JJJ JCLLIB ORDER=PROCLIB PATH
//PROC3 PROC
//STEP2.DD1 DSN=NEW NAME,DISP=SHR


THIS IS D WAY....
THIS PROG. WILL DO NOTHING IT'S JUST AN EXAMPLE

As picture clause for variable b is x(2), which means that
it can accept both numeric and characters of length 2, but
the care we should take here is that we should enclose them
in the single quotes, therefore to my expectation option b
is write.

IN SORT, YOU CAN USE JOINKEYS AND CAN TAKE 50 COMMON
RECORDS IN B/W 2 I/P FILES AND WRITE TO O/P FILE.

it's easy write restart=step57 in job parameter and write cond in 58th step like cond = (x,eq) where x is expected return code of 57th step.

In the jobcard, Give restart=step7, code cond=(0,le) from
step8 - step14, Give a null stmt(//) after step15. That's
it your requirement is met.

Simplest way:
There is an utility IEBEDIT which is used to execute only
few particular steps from 'n' steps in a jcl.

//JOBCARD
//STEPNAME EXEC PGM=IEBEDIT
//SYSUT1 DD DSN=MYPRGM.DSN,DISP=SHR
//SYSUT2 DD SYSOUT=(*,INTRDR)
//SYSIN DD *
EDIT TYPE=INCLUDE STEPNAME=(STEP7,STEP15)
/*
//

MYPRGM.DSN = The name of the dataset that has the actual
JCL.

First thing is we can see this kind of differece only in VB
files not in fixed block files.

LRECL of VB file will contain the maximum record length of
a file + 4 bytes RDW(Record Descriptor Word) field which
gives the length of the record as the file contains
variable record lengths.

Example : if we have EMP-FILE VB file which contains 80
THRU 100 CHARECTERS

So the LRECL of this file is going to be 100+4 which is 104
bytes.

sysin dd * we cannot use in procedure,15 instream proc we
can code.we can call instream to catalog.but we cannot call
catalog to instream

If table is empty then we alter this column to any length,
but if some data got inserted into the table then we can
also decrease the column length upto largest data size
available in that perticulat column.

One can use Inner Join to get data from two tables.

SUBCRIPT:
CAN BE INCREMENT OR DECREMENT USING ARITHMETIC OPERATIONS
INDEX:
CAN BE INCREMENT OR DECREMENT USING SET VERB

we cannot write when disp is share

No, It will not work. SELECT DISTINCT works only for single
cloumn.

DISTINCT can be applied multiple times only when you want
to apply aggregate functions such as COUNT, AVG & SUM.
e.g.
SELECT COUNT(EMPNO)/COUNT(DISTINCT(WORKDEPT)), COUNT
(DISTINCT(JOB))
FROM DSN8810.EMP

Dead lock time out erro occurs in the following case:
If two or more programs acquired exclusive lock on the
data,which may be needed for other programs without that
data which can not proceed further.

Solution: You can roll back current unit of work for one of
the programs after preset time interval for deadlocks and
terminate that program.

is there identity column in this table, for example, if
there is a column indexnum int(supposed start from 1), you
can use the Update Table Set XXX=XXX where indexnum < 101

yes

We can increment the count for each reading of record in a file.
Read file
count = count + 1
At end
display count

Label record is standard means it will use disk files. But
tape files can have standard label too.

If the label record is omitted it should be a the tape file
without any begin and end blocks on the tape.