Whether you use a single buffer or multiple buffers depends on whether you are issuing IXLCACHE multiple times, whether all the data resides in contiguous storage, and whether performance is a major factor. If you want to provide real buffer addresses, you can only use BUFLIST.

When you pass IXLCACHE a single buffer, IXLCACHE creates a buffer list for that buffer in the same manner as if you were specifying BUFLIST. If you invoke IXLCACHE multiple times, you can obtain better performance if you use BUFLIST instead of BUFFER and allow IXLCACHE to build the buffer list on each invocation. Using BUFLIST also lets you avoid having to move data from multiple storage areas into a single buffer before passing it to IXLCACHE.