|
View previous topic :: View next topic
|
| Author |
Message |
murugan_mf
Active User
.jpg)
Joined: 31 Jan 2008
Posts: 148
Location: Chennai, India
|
|
|
|
Hi all,
I am pretty new to IMS and having some doubts on logical relationship.
How to find out the wheher the logical relation is uni-directional or Bi-directional by viewing the DBD?
Will there be any separate DBD defined for this logical relationship? |
|
| Back to top |
|
 |
Sandy Zimmer
Active Member
Joined: 13 Jun 2007
Posts: 826
Location: Wilmington, DE
|
|
|
|
| An IMS database is defined first as a physical database. It then has the same logical definition. They match. However, you can define that physical database with a different view - a separate logical view. There are very specific rules for these separate logical database views. Yes, it will have it's own DBD. |
|
| Back to top |
|
|
murugan_mf
Active User
Joined: 31 Jan 2008
Posts: 148
Location: Chennai, India
|
|
|
|
Sandy,
Thanks for your reply.
Can you please provide me any links/manuals which explain logical
relationship with detailed examples.
I tried but unlucky!! |
|
| Back to top |
|
|
Sandy Zimmer
Active Member
Joined: 13 Jun 2007
Posts: 826
Location: Wilmington, DE
|
|
|
|
| Well, I do not have any. Let me look thru some of my "old" manuals. Is this a job issue (need to know) or just curiosity? Many high transaction processing installations do not allow a logical definition that differs from the physical. Nor do these installations allow "search fields". |
|
| Back to top |
|
|
murugan_mf
Active User
Joined: 31 Jan 2008
Posts: 148
Location: Chennai, India
|
|
|
|
Sandy,
As of now I am testing online screens..so It will be better to know. |
|
| Back to top |
|
|
Sandy Zimmer
Active Member
Joined: 13 Jun 2007
Posts: 826
Location: Wilmington, DE
|
|
|
|
If you are testing online screens, then you should already have the DBD. What is your SPECIFIC question and/or problem?
Please post the DBD and what you are trying to do. |
|
| Back to top |
|
|
murugan_mf
Active User
Joined: 31 Jan 2008
Posts: 148
Location: Chennai, India
|
|
|
|
As of now there were no problems with my testing.
I have seen a DBD having LCHILD
LCHILD NAME=(XYZ,DB1),POINTER=INDX
If I go view thru File-Aid for ims I could not see the segment XYZ.
How to get the information about this segment?
If i want to write a program with GU call on that segment which database
is requied and how the psb should look like and How can prepare the call statement?
this is totally confusing.. |
|
| Back to top |
|
|
Sandy Zimmer
Active Member
Joined: 13 Jun 2007
Posts: 826
Location: Wilmington, DE
|
|
|
|
If i want to write a program with GU call on that segment which database is requied and how the psb should look like and How can prepare the call statement?
Does your current program look at the same logical database as the physical definition?
I have seen a DBD having LCHILD LCHILD NAME=(XYZ,DB1),POINTER=INDX
The database statement that you provided is looking at the logical child. The first thing you should do is take a look at that database - you could not see the segment because it is a pointer. Think back on how IMS works. It has pointers - for instance physical twin forward and backward pointers. These are defined at inception of the database and how they are defined dictates performance. So, you need to look at the REAL matching physical/logical database. |
|
| Back to top |
|
|
Sandy Zimmer
Active Member
Joined: 13 Jun 2007
Posts: 826
Location: Wilmington, DE
|
|
| Back to top |
|
|
murugan_mf
Active User
Joined: 31 Jan 2008
Posts: 148
Location: Chennai, India
|
|
|
|
| Thanks a Ton Sandy |
|
| Back to top |
|
|
PeterHolland
Global Moderator
Joined: 27 Oct 2009
Posts: 2481
Location: Netherlands, Amstelveen
|
|
|
|
Manual SC19-2479-00
IBM IMS Library Integrity Utilities for z/OS User’s Guide Version 2 Release 1
describes a utility FABNRVRS that will output all DBD/PSB/ACB information
you are interested in. |
|
| Back to top |
|
|
|
|
