Previous topic |
Next topic |
Contents |
Glossary |
Contact z/OS |
PDF
How are data sets named? z/OS concepts |
|
When you allocate a new data set, you must give the data set a unique name. A data set name can be one name segment, or a series of joined name segments. Each name segment represents a level of qualification. For example, the data set name VERA.LUZ.DATA is composed of three name segments. The first name on the left is called the high-level qualifier (HLQ), the last name on the right is the lowest-level qualifier (LLQ). Segments or qualifiers are limited to eight characters, the first of which must be alphabetic (A to Z) or special (# @ $). The remaining seven characters are either alphabetic, numeric (0 - 9), special, a hyphen (-). Name segments are separated by a period (.). Including all name segments and periods, the length of the data set name must not exceed 44 characters. Thus, a maximum of 22 name segments can make up a data set name. For example, the following names are not valid data set names:
The HLQ for a user's data sets is typically controlled by the security system. There are a number of conventions for the remainder of the name. These are conventions, not rules, but are widely used. They include the following:
|
Copyright IBM Corporation 1990, 2010
|