What is scratch and no scratch in GDG?
noempty is given when you want to repalce your new veresion with oldest version. scratch is given when you want delete your oldest version of gdg member physically not logically. empty is given when you want to repalce your new version by replacing all your oldest version.
What is scratch in GDG?
Scratch means that when a version of the GDG is deleted because of some reason(either due to user request or due to expiry or maximum limit for GDG is exceeded), then the dataset must be Physically deleted from the system.
What is scratch in mainframe?
The SCRATCH statement is used to scratch a data set or member from a DASD volume. A data set or member is scratched only from the volumes designated in the SCRATCH statement. This function does not delete catalog entries for scratched data sets. The syntax of the SCRATCH statement is shown as follows. …
How do I allocate a base in GDG?
Answer
- Create a GDG file.
- Create a model or template for the individual generations of data sets.
- As a test you can create your first generation of data sets by running this JCL example.
- Because the Apply or Capture log file is not referenced by a DD statement you must use IEBGENER to copy your app.
What is the maximum limit of GDG?
The LIMIT parameter on the IDCAMS DEFINE GDG command is changed to accept a maximum value of 999 for extended GDGs. The previous maximum LIMIT value of 255 still applies to GDGs which are not defined as EXTENDED.
How do I increase my GDG limit?
If you use the access method services ALTER command to increase the GDG limit, no rolled-off GDSs or deferred roll-in GDSs are rolled in. When you increase the GDG limit, you must use the ALTER ROLLIN command to roll in the rolled-off generations if you need to access them.
How do I check my latest GDG version?
It is possible to see all GDG versions by using command DSLIST ‘GDG name’ in the command line ,then it lists all gdg versions and check Latest Version. Try issuing teh GDG base name with (0) as the version in the JCL. That would give the latest version.
How many generations are possible under a GDG?
The maximum number of generations that a GDG can hold is 255. While executing on a mainframe environment, SAS can access the GDG feature, write SAS data into the generational datasets, and text data into the generations of a GDG.
What is GDG model?
You must provide a data control block (DCB) to be used when GDG entries are created. You can provide it when you define the generation data group (GDG) model data set. To define the GDG model data set, use the z/OS® program IEFBR14.
Can we alter GDG limit?
What is Listcat?
LISTCAT command in VSAM is used to view the properties of VSAM file like volume details, space details, path details, and catalog details. LISTCAT can list many properties like cluster, data, index, spae details, history, volume and much more.
How can check GDG base properties?
How to see and read the properties of a GDG?
- In the ISPF command line, you can issue a command ‘TSO LISTC ENT(‘GDG-BASE-NAME’) ALL’
- Use LISTCAT ENTRY ‘GDG-NAME’ ALL in the IDCAMS utility of the JCL.
- Use a utility called Fileaid if your site supports Fileaid.
How does noscratch and noempty work on GDG?
Muthuvel. Noscratch : It will not delete the GDG versions when the max number of versions for the GDG is reached. scratch : It will scratch the older versions of the GDG, giving space for the newer versions. NoEmpty : It will not empty the GDG versions, rather it will delete the older versions of the GDG.
Can a noempty delete older versions of GDG?
NoEmpty : It will not empty the GDG versions, rather it will delete the older versions of the GDG. Correct me if i am wrong. Nobody is perfect.
What’s the difference between empty and noempty GDG?
EMPTY specifies that all existing generations of the GDG are to be uncataloged whever the generations of GDG reached the maximum limit NOEMPTY specifies that only the oldest generation of the GDG is to be uncataloged if the limit is reached SCRATCH/NOSCRATCH – These two parameters are mutually exclusive.
How to limit the number of generations in A GDG?
The number of generations that can exist in this GDG is limited to ten. NOEMPTY parameter is used to specify , Once the limit is reached, the system is instructed to uncatalog the oldest generation data set within the GDG. SCRATCH parameter is used to specify to physically delete the data set which was uncataloged.
