The Question is:
What are the signifigance of multiple data areas in a indexed fdl?
The Answer is :
The data areas permit you to locate and tune the component areas of an
RMS indexed file. For details on indexed files and indexed file design,
please see the RMS documentation in the OpenVMS manual set; specifically
see the following:
Guide to OpenVMS File Applications
OpenVMS Record Management Services Reference Manual
OpenVMS Record Management Utilities Reference Manual
In a nutshell, multiple areas are required to enable multiple bucket sizes.
Multiple bucket sizes are often desirable based on access patterns for the
various keys in the file (smaller for random access, larger for sequential
access.). Multiple areas also provide a tool for data placement, a rather
sophisticated tuning method, where sleected data is co-located in a file
(perhaps to lowest level index and the data) and others are well
seperated, perhpas even on dedicated disks.