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Conference ulysse::rdb_vms_competition

Title:	DEC Rdb against the World

Moderator:	HERON::GODFRIND

Created:	Fri Jun 12 1987
Last Modified:	Thu Feb 23 1995
Last Successful Update:	Fri Jun 06 1997
Number of topics:	1348
Total number of notes:	5438

538.0. "Migration of IDMS" by GLORY::JSTEWART () Wed Jan 17 1990 20:00


I have an account that currently is running under DOS/VSE, IDMS and
COBOL.  I am not sure if its the relational version or not. 

We have a window of opportunity with the account to migrate some of
the applications over to a VAX.  This would be a major opportunity to
further penetrate the IBM application base. 

The question that needs to be answered is;  How difficult is to
migrate this to IDMS/SQL under VMS? I have heard bits and pieces of
information that has indicated even if the IBM is running the
relational that the DB migration is painful.  Are there any tools to 
assist in the DB migration effort?  

If we find that it is painful to migrate to IDMS/SQL then we will 
definitely discuss RDB and its benefits.  In that case does anyone 
know of tools to go from IDMS on IBM to RDB?

Thanks in advance,


John

T.R	Title	User	Personal Name	Date	Lines
538.1	The data conversion is usually fairly easy !!!	SNOC01::BELAKHOVM	Target sighted - FIRE !!!	`Thu Jan 18 1990 00:33`	13
	I do not know much about IDMS/SQL, other that the first release was buggy and the local (at that time) Cullinet office was not that keen on pushing it. They were concentrating on the tools instead. If you were migrating to Rdb/VMS, which is obviously the prefered option, the Answer/DB (Sterling Software) component of VAXlink would probably be able to migrate the data fairly easily. Although, data migration is usually the easiest part of the conversion. Maybe you should contact the Center for Migration (Colorado) and see if they have any tools for the COBOL conversion. Michael
538.2	IDMS = VAX DBMS, sort of...	CSOA1::CARLOTTI	I hate when golf season ends :-(	`Fri Jan 19 1990 17:10`	16
	IDMS is a Codasyl (Network) type database system, while Cullinet's (Computer Associate's) VAX database product is a relational one. The conversion from a CODASYL database to a relational model is not trivial. There is a lot of redesign necessary for the database and hence, the programs that access that data. Also, is any part of the application written using ADS-O (ADS-O was sold as a 4GL product several years back)? This has no equivalent on the VAX (at least not that I'm aware of). The other consideration is whether the application will perform adequately using a relational database. In order for the customer to get the same performance on VAX that their getting on their IBM, an ACMS/DBMS solution might be necessary. Rick C
538.3	Another similar situation	TROA02::SPACKMAN		`Tue Jan 30 1990 23:49`	27
	I too am involved in trying to recommend a development environment for a customer that is currently using IDMS/R. They run under DOS/VSE/SP. ADS/O is the predominant development tool for their on-line applications. And, to complicate things further, it seems that they are using IDMS-DC rather than CICS for most of their applications and that CA/ICMS is not being used at all. The customer is stating that they wish to continue to support this environment, as well as do new development of applications that could be deployed on either VMS or on their IBM system. At first we were hoping that the solution might involve both Netron/CAP & VIDA for IDMS/R, but both are presenting problems (as is a VAXlink approach) due to the particular combination of tools they are using. We are now considering suggesting a migration to VMS & Rdb, so would also be interesting in knowing more about what might be available to assist with such a conversion. Can the CA Enterprise tools help at all? Also, does anyone else have any comments regarding ways to get around the "snags" mentioned above. Thanks for any help you might provide. Regards Janet