Path: utzoo!utgpu!water!watmath!clyde!rutgers!labrea!decwrl!decvax!mcnc!gatech!ukma!psuvm.bitnet!cunyvm!unknown
From: rrk@byuvax.bitnet
Newsgroups: comp.os.vms
Subject: Re: Tricky RMS/QIO problem for gurus only
Message-ID: <54rrk@byuvax.bitnet>
Date: 11 Jan 88 05:39:03 GMT
Lines: 18

You have identified a problem which must be repeatedly solved and has been
repeatedly requested from DEC via SIR's and SPR's.  DEC made a very feeble
attempt to fix the problem by providing the reverse order keys, but what
they should have done is provide another bit in the RAB for reverse order
sorting.

A small correction:  You can open a file and first do indexed I/O and then
reconnect (not reopen) for block I/O, but I would never recommend trying
to find your way around in an indexed file.  The most workable solution
(hopefully you don't have too many duplicate records) is to add a longword
to your key and define your key for no duplicates.  Then every time you
store a record, if you get a duplicate-error back, increment your longword
until it lets you store the record.  Then your key sort order will be
proper both directions, or as suggested, a time value might be better, if
you have lots of duplicates and want to avoid collisions.  Before the reverse
keys were introduced, it was necessary to store the keys twice--once in
two's compliment to provide a proper reverse sort.  Now at least the size
of the data buckets are not increased.