So what doesn't make sense?  Sure, you can do a backward read of a
KSAMXL file (FINDN/FREAD). The DBGet error 14 makes sense in that
you've established a chain of all entries(DBFIND, key @), so when
reading this list of sorted entries backwards, one should expect to
get 'beginning of chain', likewise 'end of chain' (DBGet error 15)
reading forward (DBGET(5)).  Keep in mind that the DBFIND, mode 1,
qualifier @ essentially established a logical chain of all master
entries in sorted order.  And trying to read backwards when you're
already pointing to the beginning of the logical chain (DBFIND,
DBGET(6)) can't go backwards, hence the beginning of the chain error.

 From what you've described, there doesn't appear to be any problem
with how it is operating.



At 11:22 AM 8/15/00 -0700, Tracy Pierce wrote:
>I'm trying to use Image B-Trees to gain sequential access to my Image Master
>sets.  I've done
>:DBUTIL
> >> SET VMSDB BTREEMODE1=ON
> >> ADDIndex VMSDB FLEET-MASTER
> >> ADDI VMSDB ACT-TYPES
>and have changed a couple of programs to use DBGET mode 5 & 6 (instead of 2
>& 3), and have changed the corresponding 'rewind' (DBCLOSE mode 3) to a
>DBFIND mode 1 arg @.
>
>This seems to work, at least partially:  Using FLEET-MASTER as an example,
>the DBFIND always works, and despite no record pointers it reports all 10
>records on the dataset.  DBGET mode 5 yields the first ("smallest") record;
>subsequent DBGET mode 5's yield increasing key values.  Once I've done a
>DBGET mode 5, a subsequent DBGET mode 6 goes backward (how??  backward read
>in KSAMXL file???).  But DBGET mode 6 immediately after the DBFIND just gets
>me status 14, beginning of chain.  Kind of makes sense, but not enough; Stan
>says it should work.
>
>Are there patches I've overlooked or something?
>
>:version dbutil.pub.sys
>VERSION  C.55.00 Copyright (C) Hewlett-Packard 1987.  All Rights Reserved.
>
>DBUTIL.PUB.SYS
>
>SOM #1
>$Header: nrt0.s,v 1.12 87/06/08 09:36:52 cary Exp $
>Compiled on WED, SEP 24, 1997, 10:31 AM
>S35S391C.HP30391.TURBONM
>Copyright (c) 1987  Allegro Consultants, Inc.
>SPLash! 97E 4.19
>
>t   the prior written consent of the Hewlett-Packard Company.
>his program except for archival purposes is prohibited withou
>d   in a retrieval system. Copying or other reproduction of t
>me  and shall not otherwise be recorded, transmitted or store
>987 This program may be used with one computer system at a ti
>Compiled on THU, JUN  6, 1996,  7:33 PM
>REDO.MODULE.TURBONM
>Copyright (c) 1987  Allegro Consultants, Inc.
>SPLash! 96E 4.10
>
>K Tracy Pierce, Systems Programmer
>Golden Gate Bridge, Hwy & Trnsp Dist
>PO Box 9000, Presidio Station
>San Francisco, CA  94129-0601
>mailto:[log in to unmask]
>415-923-2266