Defining a New Data Item: Summary

This topic summarizes one way to define a new data item using IXLCACHE REQUEST=READ_DATA:

To name the data item, code the NAME keyword.
To request that the system create a directory entry if one does not exist, code ASSIGN=YES, or omit the ASSIGN keyword. The system attempts to allocate the cache structure resources needed to satisfy the request. If the allocation is successful, the system creates a directory entry and registers your interest in the data item. If unallocated resources are unavailable and currently allocated resources cannot be reclaimed to satisfy the allocation, the request fails.
When you define a new data item, there is no data in the cache structure for the data item, and it is unnecessary to code the BUFFER, BUFLIST, or ADJAREA keywords.
Code the VECTORINDEX keyword.

You must assign a vector index entry by coding the VECTORINDEX keyword. If you assign a vector index entry that is currently associated with another data item, specify the name of that data item on the OLDNAME keyword. The system creates an association between the new data item and the vector index entry and registers your interest in the data item. If you also specified the OLDNAME keyword, the system deregisters your interest in the data item specified on OLDNAME.

For More Information

There are other keywords that are required and some that are optional. Some of these keywords apply to all IXLCACHE requests and others apply to just READ_DATA requests. For a description of keywords applicable to all IXLCACHE requests, see: