Specifying the Data to be Read

You issue a READ_DATA request to either define a new data item or read a currently defined data item. When you define a new data item, there is no data transferred to either your local cache buffer or your adjunct area.

When you read a currently defined data item, you can read the data item, read adjunct data, or read both. To read the data item only, identify the local cache buffers by coding either the BUFFER or BUFLIST keywords and their related keywords. Omit the ADJAREA keyword.

If there is data in the cache structure for the requested data item, the system transfers the data item to your local cache buffer.
If there is no data in the data entry, your local cache buffer is left unchanged.

To read adjunct data only, code the ADJAREA keyword and omit the BUFFER keyword. Optionally, you can code the BUFLIST keyword and its related keywords. If you code BUFLIST, BUFNUM must specify a value of zero.

If the cache structure supports adjunct data, the system returns the adjunct data to the area specified on the ADJAREA keyword.
If the cache structure does not support adjunct data, the area specified on the ADJAREA keyword remains unchanged, and appropriate return and reason codes are returned.

To read both the data item and adjunct data, code BUFFER or BUFLIST and their related keywords, and ADJAREA.