Defining and Writing a New Data Item: Summary

A previously undefined data item is one that is not defined to the cache structure. This topic summarizes a way to use the IXLCACHE REQUEST=WRITE_DATA to define and write a new data item.

To write an undefined data item to the cache structure, specify NAME for the data item and WHENREG=NO to indicate that you currently do not have registered interest in the data item.
Assign a vector entry on the VECTORINDEX keyword. If the vector entry you assign is currently associated with another data item, specify OLDNAME to identify the other data item.

The system attempts to allocate the cache structure resources to satisfy the write request. If the allocation is successful, the system creates a directory entry and registers your interest in the data item. If the resources are unavailable to satisfy the allocation, and the system is unable to reclaim resources currently in use, the request fails.

Your request must indicate whether the data item you are writing is the same as the copy on permanent storage. If it is the same, specify CHANGED=NO or omit the parameter to use the system default. The system does not allow you to overwrite changed data with unchanged data.