Clarification required on GN with out SSA

hemanthj642 · New User Joined: 14 Sep 2005 Posts: 21

Hi,
I have a doubt on sequence of accessing segments in IMS when GN is used with out SSA.
for eaxample there are 3 segments A,B and C.
Here A is a root and B is dependent on A and C is a dependent on B.
Here B has multiple occurences B1,B2,B3 and C has multiple occurences C1,C2,C3.
I am confusing whether accessing of segments would be A1,B1,C1,C2,C3,B2,B3 OR A1,B1,C1,B2,C2,B3,C3.
so far I am under impression that it would be A1,B1,C1,C2,C3,B2,B3 but recently when I am going through the manulas I have
seen the below scenario.

The scenareo is .. there is COURSE segment(Root) under COURSE there are childs INSTRUCTOR,STUDENT AND PLACE.
Under INSTRUCTOR segment we have multipla occurences of REPORT(REPORT1 and REPORT2) segments.
STUDENT segment has multiple occurences (STUDENT1 AND STUDENT2).
Under STUDENT segment we have GRADE segment which also contains mutilple occurences(PASS and INC)
The sequence of accessing segments shown are COURSE,INSTRUCTOR,REPORT1,REPORT2,STUDENT1,PASS,STUDENT2,INC,PLACE.

Can anyone help me clarifying the above matter?

Thanks in Advance .

Nic Clouston · Posted: Fri Nov 25, 2011 12:49 pm

Where is the discrepancy - the data you show seems to match the hierarchical sequence (top down, left to right)?

enrico-sorichetti · Posted: Fri Nov 25, 2011 12:54 pm

why not use DFSDDLT0 ( IMS DLI test program ) to verify Your thinking ?

hemanthj642 · New User Joined: 14 Sep 2005 Posts: 21

Hi Nic,

We have multiple occurences of STUDENT segmenst(STUDENT1,STUDENT2) under STUDENT segment we have GRADE segment which also have multiple occurences(PASS,INC).
GRADE segment is the loweset level segment.
As per my understanding since GRADE is lowest level segment DLI has to access multiple occurences GRADE(PASS,INC) after accessing those 2 occurences DLI has to come back and access second occurence of STUDENT segment (STUDENT2) in that case the sequence will be COURSE,INSTRUCTOR,REPORT1,REPORT2,STUDENT1,PASS,INC,STUDENT2,PLACE. But I saw one of the manuals sequence of these segments shown below. COURSE,INSTRUCTOR,REPORT1,REPORT2,STUDENT1,PASS,STUDENT2,INC,PLACE.
After accessed PASS it doesn't access INC instead it came back accessed STUDENT2 then accessed INC, thats where my doubt is.

Hi Enrico,
I could test it myself and learn but my current project I dont have IMS environment hence I didn't do that.
I have used IMS previously and I dont want to loose that skill so whenver I have time I brsuh up myself reading forums and manuals.

Thanks,

Nic Clouston · Posted: Fri Nov 25, 2011 10:02 pm

There may not be a segment with INC. As far as I can make out 'PASS' and 'INC' are values that the GRADE segment can hold.

Which manual are you referring to?

hemanthj642 · New User Joined: 14 Sep 2005 Posts: 21

Hi Nic,

The below is the address where I saw the info.

publib.boulder.ibm.com/infocenter/dzichelp/v2r2/index.jsp?topic=%2Fcom.ibm.ims11.doc.dag%2Fims_dbtypes.htm

After click the above site you will get a page where if you see the left side yow will have 'contents ' there you can find 'HOW DATA IS STORED IN A DATABSE SECTION'. Please click that it will take u to the next page where you can see the info which I have mentioned.

IMS Version 11 > IMS administration > Database administration > General database concepts, standards, and procedures > Introduction to IMS databases > Database concepts and terminology > How data is stored in a database

Thanks..

Ed Goodman · Active Member Joined: 08 Jun 2011 Posts: 556 Location: USA

I THINK I see what you mean. It's a little confusing because of the picture.

However, that "INC" is actually a child of the second STUDENT segment. It is drawn directly behind the "PASS" as if it were under the first STUDENT. If you look REALLY REALLY closely, you'll see a vertical line connecting it to the second STUDENT segment.

hemanthj642 · New User Joined: 14 Sep 2005 Posts: 21

Thanks Ed .. I got the point ..