Warning for those with Suprtool AND Netbase:
 Remote Jumbo datasets
 =========================================================
 
Since MPE/iX 5.0, IMAGE/SQL has provided "jumbo datasets" to allow you
to create datasets larger than the MPE 4 gigabyte file limit. It does
so by splitting the (logical) dataset into several physical files,
stored in the POSIX namespace. So SET05.DATA.SALES would be split into
/SALES/DATA/SET05.001, /SALES/DATA/SET05.002, etc.
 
Suprtool attains its impressive serial read speed by reading datasets
directly, with MR;NOBUF access. It establishes the physical
filename(s) of the dataset, performs the serial MR;NOBUF reads, and
deblocks the records to write them to the output file. Suprtool has
supported jumbo datasets since their first release, and will read the
"chunks" of the datasets automatically and transparently.
 
Netbase, from Quest Software, shadows files across CPUs. It allows
programs to access remote files and databases as though they were on
the local CPU. For IMAGE/SQL, it traps the intrinsic calls to the
databases, and satisfies the requests with data from the remote
database, and similarly processes regular file system calls.
 
Netbase supports the shadowing of these Jumbo datasets, but
does not yet support NFA(Network File Access) directly to the POSIX
namespace portion of these datasets. This functionality is currently
under development at Quest. Accessing these Jumbo datasets with image
intrinsics is supported via NFA.
 
What does this mean to you? If you're using NFA to access a remote
database, and you convert a dataset in that database to jumbo format,
Suprtool will be unable to perform MR;NOBUF reads to the "chunks" of
the dataset as Netbase cannot trap the calls to the POSIX files.
 
 Workarounds?
 - Don't use jumbo datasets.
 - SET PRIVMODE OFF in Suprtool. This forces Suprtool to use only Image
 calls when accessing the data, and Image manages the physical disc reads
 to the posix files on the remote machine. Disadvantage: considerably
 slower than MR;Nobuf access.
 - Run Suprtool on the remote machine, extract the data required, then
 either copy that data to the local machine, or read the extracted file
 via Netbase.
 
Please contact Robelle Tech Support if you require further information:
    [log in to unmask]
    (800) 561-8311
 
 
 
__________________________________________________________
| Hans Hendriks <[log in to unmask]>    Ph:   (800) 561-8311
|             http://www.robelle.com  Fax:  (604) 582-1799