| re .0
> My customer's present application presently runs in an
> IBM4083/CICS/VSAM/Cobol environment. He would like to migrate to
> a VAX/VMS/Rdb environment, but would also like to convert most of
> his data (about 3 million records occupying about 1 gigabyte).
You did not specify the operating system that runs on the IBM. I hope it is
MVS.
> 2. RdbAccess for RMS - scheduled to be released in Q3FY91 and capable
> of providing a direct VAX SQL access gateway to VSAM data sets.
> Data definitions must be defined in CDD/Plus. Relational operations
> can be performed. Data does not actually reside in Rdb.
RdbAccess really accesses RMS files. It can access VSAM files as long as you
use it with DTF installed (which makes VSAM files appear as RMS files).
> 3. VAXlink - accesses VSAM and IMS-DB through SNA gateway.
VAXlink needs the proper extractor to be installed on the IBM mainframe; that
extractor is a 3-rd party product sold by Sterling Software. As far as I know,
we (digital) only sell and support that version that runs on MVS. Sterling
Software may be able to supply one that runs on VSE, but you have to consider
the licensing cost and installation effort - all for a one-time job.
> 4. DTF (Data Transfer Facility) - Transfers data from VSAM to RMS
> files.
Again, as far as I know, we only provide the version that runs on MVS. I
believe a VM/CMS version is in FT. Here also, you need to balance the licensing
cost and installation effort with the benefits you expect to achieve.
I think one key figure is :
> his data (about 3 million records occupying about 1 gigabyte).
All three solutions above involve data transfer over an SNA gateway. I believe
the limiting factor will be the gateway iself. You may need a high-speed
gateway (channel attached).
My suggestion : use the sneakernet approach - extract the data from the IBM
machine on tapes, move them to the VAX and load the data in RMS files. Of
course, it will not exactly be *that* easy - you still need to write some code
to do the actual data type conversions. ;-)
/albert
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| Just a suggestion, but sneaker net is the appropriate solution for the
customer. The customer does not need a permanent link between Rdb and
VSAM and therfore would not want to license software on their IBM and
Digital hardware.
Writing the code to convert the IBM tapes is no big deal (he says never
having written it). Does anyone know of where the command procedure is
that pulls data off a tape that was created on an IBM machine? I have
seen it referenced somewhere on the network.
Once the data is loaded into RMS files, all you need to do is write a
program that will do any of the necessary data conversions and then load
the data into Rdb.
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