Regarding GN call

garv_fundu · New User Joined: 02 Nov 2006 Posts: 22

Suppose A is the root segment
B and C are the child segments of A
D is the child seg of B
E is the child seg of C

If currently we are at position B and we place a Call GN A
what will be the result?

guptae · Posted: Fri Nov 10, 2006 10:38 pm

Hi there,

we will get next segment of A means if we have two occurance of A say for key a1,a2 & we are at the child of a1 which is b1(segment b) then if we issue GN a we will get a2.

Hope it is clear

garv_fundu · New User Joined: 02 Nov 2006 Posts: 22

guptae · Posted: Sun Nov 12, 2006 9:35 pm

Hi there,

if we have structure like that

a1,a2 r two occurance of A, b1, b2 are child of a1 if r pointer is on b1 if we give GN A it will fetch b2
a1 is occurance of A, b1,is child of a1 if r pointer is on b1 if we give GN A it will give end of database
GHU: will get hold the segment & establish the parentage

rahul_kolhe · New User Joined: 08 Nov 2006 Posts: 15

please explain in detail : a1,a2 r two occurance of A, b1, b2 are child of a1 if r pointer is on b1 if we give GN A it will fetch b2

I tried your first answer and it was right : [we will get next segment of A means if we have two occurance of A say for key a1,a2 & we are at the child of a1 which is b1(segment b) then if we issue GN a we will get a2.
]
[/quote]

guptae · Posted: Mon Nov 13, 2006 9:55 am

Hi Rahul,

What u want to know exactly?

Bitneuker · Posted: Mon Nov 13, 2006 8:07 pm

Guptae: I think Rahul is confirming your answer

For Rahul:

A GN call acts dependent on the SSA. If none is supplied it reads and returns the database sequentially in hierarchy: top-down-left-right. If qualified it will still read identically but return only the segments that meet the qualification. Each successfull GN-call establishes position.

GHU locks the segment for a subsequent delete or update. GHU also returns the first segment to meet the qualification and normally finds its way via the index. GHN returns and locks the next segment to meet the qualification.

Via Google one can find some more basics.
This one seems all right.

rahul_kolhe · New User Joined: 08 Nov 2006 Posts: 15

Thank you George,

The link is very useful and answer was perfect and what I wanted.

Since I was facing issue where my GN call was looping and never returning GE statcode(may be looking for whole DB), Use of GNP solved it but still I was confused. Above answer cleared all doubts.

Thank you again.
Rahul

garv_fundu · New User Joined: 02 Nov 2006 Posts: 22

hi guptae,

reg ur post:

a1 is occurance of A, b1,is child of a1 if r pointer is on b1 if we give GN A it will give end of database
GHU: will get hold the segment & establish the parentage

if after we get end of database, immediately we give a GHU call for the segment A, what will be the result?

Bitneuker · Posted: Tue Nov 14, 2006 3:35 pm

Bitneuker · Posted: Tue Nov 14, 2006 3:45 pm

gav_fundu please read my prior post.