Retaining and Positioning Data Buffers

Some operations retain positioning while others release it. In a similar way, some operations hold onto a buffer and others release it with its contents. Table 1 shows which RPL options result in the retention of data buffers and positioning, and which options result in the release of data buffers and positioning.

Table 1. Effect of RPL options on data buffers and positioning
RPL Options	Retained	Released
SEQ	*
SKP	*
DIR NSP	*
DIR (no NSP)		*
DIR LOC	*
UPD (with GET)	*
any (with POINT)	*

Note:

A sequential GET request which was positioned on the last record of a buffer will release that buffer and position to the next buffer (control interval) to return the next sequential record.
The ENDREQ macro releases data buffers and, if any, shared resources or RLS, index buffer, and positioning.
Certain options that retain positioning and buffers on normal completion cannot do so if the request fails with an error code. See z/OS DFSMS Macro Instructions for Data Sets to determine if positioning is maintained if a logical error occurs.
Use the ENDREQ macro to end requests that hold position before reusing the RPL, to avoid unpredictable results. The RPL that you ENDREQ must be the same RPL that was used to issue the initial request.
The POINT request, regardless of the RPL options, will always hold position because it only positions and does not return a record. A sequential GET following the POINT will retrieve the record; a direct GET establishes its own position and may or may not retrieve the record to which POINT was positioned. The request following a POINT will either keep position or release it based on Table 1.

The following operation uses but immediately releases a buffer and does not retain positioning:

   GET  RPL OPTCD=(DIR,NUP,MVE)