ABCs of z/OS System Programming Volume 3 - IBM Redbooks

5.28 Developing naming conventions
Setting the high-level qualifier standard
First character Second character Remaining characters
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Type of user Type of data Project name, code, or
userid
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A - Accounting Support P - Production data Example:
D - Documentation D - Development data
E - Engineering T - Test data 3000 = Project code
F - Field Support M - Master data
M - Marketing Support U - Update data
P - Programming W - Work data
$ - TSO userid
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Figure 5-28 Setting data set HLQ conventions
Developing a data set naming convention
Whenever you allocate a new data set, you (or the operating system) must give the data set a
unique name. Usually, the data set name is given as the dsname in JCL. A data set name can
be one name segment, or a series of joined name segments; see also 2.2, “Data set name
rules” on page 19.
You must implement a naming convention for your data sets. Although a naming convention is
not a prerequisite for DFSMS conversion, it makes more efficient use of DFSMS. You can
also reduce the cost of storage management significantly by grouping data that shares
common management requirements. Naming conventions are an effective way of grouping
data. They also:
► Simplify service-level assignments to data
► Facilitate writing and maintaining ACS routines
► Allow data to be mixed in a system-managed environment while retaining separate
management criteria
► Provide a filtering technique useful with many storage management products
► Simplify the data definition step of aggregate backup and recovery support
Most naming conventions are based on the HLQ and LLQ of the data name. Other levels of
qualifiers can be used to identify generation data sets and database data. They can also be
used to help users to identify their own data.
Chapter 5. System-managed storage 289