HLQ

High-Level Qualifier

Enhanced Definition

The first part of a dataset name that typically identifies the owner or category of the dataset. HLQs are used for organizing datasets and controlling access through security systems.

Key Characteristics

- First qualifier in dataset name
- Usually 1-8 characters
- Often represents user ID or project
- Used by security systems for authorization
- Basis for dataset organization
Naming Conventions:
- User ID: USER1.MYAPP.DATA
- Project: PROJ.PROD.MASTER.FILE
- Application: PAYROLL.WEEKLY.EXTRACT
- System: SYS1.PROCLIB
Security Implications:
- RACF profiles often based on HLQ
- Authorization rules by HLQ pattern
- Automatic dataset protection
- User ID as HLQ for TSO users
- User datasets: userid.*
- Production: PROD.*
- Test: TEST.*
- System: SYS1.*, SYS2.*
- Application: appname.*

Use Cases

- Organizing datasets by owner or project
- Implementing security policies
- Dataset classification and management
- Automated backup selection
- Storage management policies
## I