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neelesht
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Joined: 24 Jul 2006
Posts: 99
Location: Los Angeles
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Hi All,
Not sure this post should have been in in IMS forum or DB2, please move it if this is not the right place for this topic.
This was asked to me in an interview.......Client wants to migrate from IMS (DB) to DB2. He said programming changes are ok but what about data, how we will move it or what exactly needs to be done, is there any specific tool or anything which you can think of.
I was not sure......can someone help me with this or is there any link ?
Thanks
Neelesh |
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dick scherrer
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Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
| Quote: |
| He said programming changes are ok but what about data, |
Either this is a trick question or the client is only interested in your database knowledge as it relates to handling the data.
If there is to be no change to the structure of the database, creating db2 tables from ims tables can be as simple as unloading the data from ims, defining the new tables to db2 and loading the data from the qsam files. Some thought will probably be needed to define the db2 indexes.
fwiw - the programming effort to convert from ims navigation to db2/sql takes more than just a little work. Not necessarily difficult, just a lot of it. . . |
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neelesht
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Joined: 24 Jul 2006
Posts: 99
Location: Los Angeles
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So, it doesn't matter whether we are migrating from IMS or just unloading and loading the data back to DB2......right ? (Except the Index and Table creation part)
Even I thought the programming effort would be much more.
Thanks Dick. |
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dick scherrer
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Joined: 23 Nov 2006
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You're welcome 
It doesn't much matter if all of the db2 entities have already been defined. . .
Otherwise, all of the tables would need to be defined, permissions granted, etc. . .
I thought the question was somewhat "limited"  |
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neelesht
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Joined: 24 Jul 2006
Posts: 99
Location: Los Angeles
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Hi,
Apologies for coming back so late.
So, transferring data from Hiererchial to RDMS is just unload and load.....nothing else.
I have just started on the project and still waiting for the requirement so dont have much idea and didnt find any good document on net.
Thanks
Neelesh |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
| Quote: |
| So, transferring data from Hiererchial to RDMS is just unload and load.....nothing else. |
Possibly. . . But Only If the existing design is a "good" design and there is to be no change to the current table design.
As i mentioned originally, the question seems "limited".
You also seem to want to hear that this will be a snap of the fingers. It may, but it also may not. . . Better to plan on significant effort and then have a pleasant surprise rather than plan on a small effort and then having to manage both yours and your manager's disappointment. |
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neelesht
New User
Joined: 24 Jul 2006
Posts: 99
Location: Los Angeles
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Hey Dick,
Continuing our discussion......we came up with some approach and I will let you know what xactly is that approach before that I have a qns
Is there anyway to capture what was the last call I made to IMS e.g.
CALL 'CBLTDLI' USING FUNC-ISRT
PCB-YYYY
XXXX-SEG
UNQ-SEGMENT-SSA.
Now once I make this call and then call a para to determine the response of the DATABASE at that point of time how can I know which call I had made to DB (whether ISRT or REPL or GU or GN). I know this is more of a shop specific qns but still do you think that information is stored somewhere.
Thanks, I will surely let you guys know the approach we are finalizing for IMS to DB2 migration.
Regards
Neelesh |
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dick scherrer
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Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello,
Database modifications could be tracked (not in real-time, though) but i've never heard of anything that provides the "last request" info. One could conceivably write code that intercepted every call to CBLTDLI, recordrd the request and then recorded the response from ims before returning to the actuall caller. Not a trivial task to intercept and inter-leave all of the activity into and back from the database. . . 
How would this be part of converting to db2? Keep in mind that thousands upon thousands of applications have been converted to db2 with no need for something like this. . .
As always, if you explain things more clearly, someone has a better change at making a useful suggestion. |
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