Retrieving QSAM files
You retrieve QSAM files, cataloged or not, by using job control statements or environment variables.
- Cataloged files
- All data set information, such as volume and space, is stored
in the catalog and file label. All you have to code are the data set
name and a disposition. When you use a
DD
statement, this is theDSNAME
parameter and theDISP
parameter. When you use an environment variable, this is theDSN
parameter and one of the parametersOLD
,SHR
, orMOD
. - Noncataloged files
- Some information is stored in the file label, but you must code the unit and volume information, and the dsname and disposition.
If you are using JCL, and you created the file
in the current job step or in a previous job step in the current job,
you can refer to the previous DD
statement for most
of the data set information. You do, however, need to code DSNAME
and DISP
.