VSAM LRECL for a primary index

The format of a VSAM LCRECL for a primary index depends on whether it is currently on a storage device, in the buffer pool, or being returned by the buffer handler.

Format on a storage device or in the buffer pool

The following figure shows the format on a storage device or in the buffer pool.

Figure 1. LRECL format on storage device and in buffer pool
Graphic is a 3 column, 1 row table. Column 1 is labeled "DEL. FLAG." Column 2 is labeled "PTR" and references note 1 below. Column 3 is labeled "ROOT KEY VALUE."

Note:

1.
Four-byte RBA pointer to VSAM database root segment whose key value is the same as the value in the next field of this segment.

Format as returned by the buffer handler

The following figure shows the VSAM LRECL format as returned by buffer handler (1).

Figure 2. VSAM LRECL format as returned by buffer handler
Graphic is a 5 column, 1 row table. In front of the table is a reference to note 1 below. Column 1 is labeled "PTR" and references note 2 below. Column 2 is labeled "SEG. CODE." Column 3 is labeled "DEL. FLAG." Column 4 is labeled "PTR" and references note 1 below.
Notes:
1.
Same as buffer pool format, except for pointer and segment code in front.
2.
Four-byte pointer with value of zero.
3.
The segment code value is 01.
4.
Four-byte RBA pointer to VSAM database root segment whose key value is the same as the value in the next field of this segment.

VSAM block format on a storage device or in the buffer pool

The following figure shows the VSAM block format on device and in buffer pool.

Figure 3. VSAM block format on device and in buffer pool
Graphic is a 4 column, 1 row table. Columns 1 through 3 are labeled "LRECL." Column 4 is labeled "VSAM INFO."