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Lkmi
New User
Joined: 04 Mar 2005 Posts: 53 Location: Newyork
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Iam working on a requirement that aims at converting a Mainframe application from VSAM to DB2.
At this point Iam are looking for presentations/documents/statistics/metrics/white papers/case studies in support of the conversion to present to the Client.
I was able to find lot of information on the internet regarding the advantages of DB2 over VSAM but not much of quantitative Information.
Do you have (or) Are you aware of any presentations/metrics/document on how DB2 performs better than VSAM??
Any inputs on this regard at the earliest will be appreciated. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
Depending on your situation, going to DB2 may not perform any better than the existing VSAM related to resources used (cpu, space, i/o's).
A BIG payoff in converting the app to DB2 is that there are many more things you can do with the DB2 environment - connectivity, integration, reporting via point&click tools (like Crystal). The DB2 world also has far better ability to support many concurrent batch/online users.
Something to be aware of is that in the VSAM world, the application developers are usually in complete control of the data definitions and physical files. This will most likely not be the case with DB2. If there is already a database administration group, they will most likely be responsible for the new addition(s) to the DB2 world. |
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DavidatK
Active Member
Joined: 22 Nov 2005 Posts: 700 Location: Troy, Michigan USA
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Lk,
I agree with Dick, except maybe his first sentence. DB2 is a resource hog. It will definitely use more resources. CPU, Space, I/Os, everything.
If you need to be fast, small and inflexible, use VSAM.
The reason to use DB2 is the flexibility that comes with it. DB2 is infinitely more flexible than native VSAM (Even though the underlying DB2 data structure is VSAM). Development time with DB2 is much less than with VSAM.
At one time, hardware was very expensive compared to personnel cost, so the programmer needed to use the best and most efficient coding available. Today however, personnel cost is the expensive part. Better to buy more hardware to support less efficient coding |
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Lkmi
New User
Joined: 04 Mar 2005 Posts: 53 Location: Newyork
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Hello,
I accept your statements. It has already been decided that the system will be converted to DB2 and as i said I need to substantiate it at this point.
Are you guys aware of any supporting presentation especially metrics??? |
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Lkmi
New User
Joined: 04 Mar 2005 Posts: 53 Location: Newyork
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Thanks Dave and Dick for the response. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hi LK,
You're welcome.
I was fairly certain the decision there was already made. Sorry that i don't have any material that has what you are looking for. I've been involved with several sites that made some kind of move to DB2. After they did any amount of testing they stopped talking about any utilization reduction. Over the years, i believe that most organizations have bought into the idea that while it does cost more, it is worth it.
I guess my thought was that the decision to move from VSAM to DB2 is not made on a technical basis (i.e. performance, etc). If your organization is looking for some kind of justification, i'd suggest quoting some of the material you found on why others have made the change.
Like Dave pointed out, machine capacity is getting cheaper while people are not. |
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Lkmi
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Joined: 04 Mar 2005 Posts: 53 Location: Newyork
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Thanks Dick |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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You're welcome |
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