Understanding the Write Operation

Assuming the list structure has been allocated to contain both data entries and adjunct areas, you can write data to any of the following with the WRITE operation:

The data entry only
The adjunct area only
Both the data entry and the adjunct area.

The only exception is when you create a new list entry in a structure that has adjunct areas; if you don't specify data to be written to the adjunct area, the adjunct area of the new list entry is initialized to zeros.

If the list structure contains adjunct areas, each list entry always contains an adjunct area. For list structures with both data entries and adjunct areas, it is possible to have list entries with either of the following:

An adjunct area but no data entry
A data entry and an adjunct area

Guide to the Topic

WRITE: Writing to a List Entry is divided into three topics:

The first topic provides information applicable to all WRITE requests:
The second topic, Updating an Existing List Entry, explains how to update an existing entry.
The third topic, Creating a New List Entry, explains how to create a new entry.