kckinney

 Profile Answers by kckinney Questions by kckinney

• Jun 8th, 2007

 

A dataset can be allocated on a volume, but not cataloged. This means you will have to explicitly code the volser(s) and unit when trying to access the DSN in the future.(Note, this is not possible under SMS as you cannot have an uncataloged dataset unless you take extreme measures. It is assumed that most mainframe systems will have SMS active.)Cataloging a dataset means registering the name, unit and volser(s) in the user catalog. (It's possible you could catalog it in the master catalog, but this is unlikely.)When accessing a cataloged dataset, you merely specify the DSN and disposition. The system then queries the appropriate catalog which supplies the unit & volser(s) of the DSN.

srikanth

• Sep 18th, 2011

 

Cataloging a dataset means all the details related to dataset like on which VOLUME and on which UNIT does the dataset reside is stored in a register when you mention CATLG in DISP parameter. So whenever you access this dataset system checks the information in register and goes to that location (vol, unit) retrieve the dataset. If dataset is not cataloged i.e., there is no information regarding the dataset in the register so system cant access that dataset in such case you have to give all details like vol, unit while accessing that dataset.