Vsam tips
1) copy vsam to flat file
2) then process the flat file in subsequent steps
3) some times vsam is empty
4) when it is empty job abends
//step3 exec pgm=sort,parm='vsamemt=yes'
//sysout dd sysout=*
//sortin dd dsn=vsam.dsn,disp=shr
//sortout dd dsn=flatfile.dsn,disp=shr
//sysin dd *
sortfields = copy
//*
2) how should be vsam file defined that it can be accessed both in cics and in batch
define shareoption(2,3)
3) vsam equivalent of tempdataset is to create vsam file with re-use option.
a dataset created with re-use can be treated as new dataset at any subsequent time.
4)vsam dataset - read only
//step1 exec pgm=idcams
//sysprint dd sysout=*
//sysin dd *
alter -
secret.ksds.data -
inhibit
alter -
secret.ksds.index-
inhibit
//*
5) how can i specify dummy vsam dataset in JCL
//step1 dd dummy,AMP='AMORG' -- tels the OS to treat the file as VSAM
6) define path creates an alias for VSAM datasets
define alias creates an alias for non-vsam dsn
7) idcams can be executed with out sysprint and sysin dd statements
8) one can speed up applications greatly by using memory cuuting down I/O
In dd statements code AMP parameters = BUFNI(index) ----- random access
BUFND(data) ---- sequential access
BUFSP(amount of virtual storage)
9) cOMP for numeric data and comp-3 for decimal data
10) fOR ksds & RRDs when delete statement is used file must be opened in I-o mode
11) one can generate a complete listing of compiler daignostic messages by using ERRMSG in the program-id.
12) using open output to load vsam will significantly improve the performance of your program using open i-o and extend will have negative importance
13) how cobol compiler gets to know that file is vsam or not
by using the organization clause hence organization cluase cannot be coded for non-vsam datasets
2) then process the flat file in subsequent steps
3) some times vsam is empty
4) when it is empty job abends
//step3 exec pgm=sort,parm='vsamemt=yes'
//sysout dd sysout=*
//sortin dd dsn=vsam.dsn,disp=shr
//sortout dd dsn=flatfile.dsn,disp=shr
//sysin dd *
sortfields = copy
//*
2) how should be vsam file defined that it can be accessed both in cics and in batch
define shareoption(2,3)
3) vsam equivalent of tempdataset is to create vsam file with re-use option.
a dataset created with re-use can be treated as new dataset at any subsequent time.
4)vsam dataset - read only
//step1 exec pgm=idcams
//sysprint dd sysout=*
//sysin dd *
alter -
secret.ksds.data -
inhibit
alter -
secret.ksds.index-
inhibit
//*
5) how can i specify dummy vsam dataset in JCL
//step1 dd dummy,AMP='AMORG' -- tels the OS to treat the file as VSAM
6) define path creates an alias for VSAM datasets
define alias creates an alias for non-vsam dsn
7) idcams can be executed with out sysprint and sysin dd statements
8) one can speed up applications greatly by using memory cuuting down I/O
In dd statements code AMP parameters = BUFNI(index) ----- random access
BUFND(data) ---- sequential access
BUFSP(amount of virtual storage)
9) cOMP for numeric data and comp-3 for decimal data
10) fOR ksds & RRDs when delete statement is used file must be opened in I-o mode
11) one can generate a complete listing of compiler daignostic messages by using ERRMSG in the program-id.
12) using open output to load vsam will significantly improve the performance of your program using open i-o and extend will have negative importance
13) how cobol compiler gets to know that file is vsam or not
by using the organization clause hence organization cluase cannot be coded for non-vsam datasets
Comments
Post a Comment