JCL DCB Parameter

Code Example

## JCL DCB Parameter

The DCB (Data Control Block) parameter defines the physical characteristics of a dataset.

### Syntax
\`\`\`jcl
DCB=(subparameter,subparameter,...)
\`\`\`

### Key Subparameters

| Subparameter | Description |
|--------------|-------------|
| RECFM | Record format |
| LRECL | Logical record length |
| BLKSIZE | Block size |
| DSORG | Dataset organization |

### RECFM Values

| Value | Meaning |
|-------|---------|
| F | Fixed length |
| FB | Fixed blocked |
| V | Variable length |
| VB | Variable blocked |
| FBA | Fixed blocked ASA |
| VBA | Variable blocked ASA |
| U | Undefined |

### BLKSIZE
- For FB: Multiple of LRECL
- For VB: LRECL + 4 (RDW)
- BLKSIZE=0: System determines optimal

### DSORG Values
- PS: Physical sequential
- PO: Partitioned (PDS)
- DA: Direct access

### DCB Merging
DCB values come from (in order):
1. JCL DD statement
2. Dataset label
3. Program DCB macro