View previous topic :: View next topic |
Author |
Message |
swapna Beginner
Joined: 28 Nov 2005 Posts: 4 Topics: 1 Location: chennai
|
Posted: Wed Nov 30, 2005 11:12 pm Post subject: logical database - physical /virtual bidirectinal |
|
|
i am going thru logical databases and found bidirectionall physicall and bidirectional virtual. i couldn't find by looking DBD, whether it has virtua or physical relation . PL. guide me _________________ Thanks,
Swapna |
|
Back to top |
|
 |
ANIL SARATHY Beginner

Joined: 30 Aug 2005 Posts: 88 Topics: 3 Location: Syracuse,New york
|
Posted: Thu Dec 01, 2005 12:20 am Post subject: |
|
|
To understand this you should know little about pointers and real and virtual logical childs
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/dfsa10f3/2.4.1.10.1?SHELF=&DT=20020905085130&
Physicall relation will have two LCHILD's in two databases. pointer = none for both lchild. RLC will not have source=
Virtual relation will have 1 LCHILd (Virtual logical child database). pointer = single or double for lchild. VLC will have source=
Code: |
VIRTUAL:
a c
lchild b pointer=sngl/dble
(rlc) b d (vlc) source=b
PHYSICAL:
a c
lchild d
pointer=none lchild b pointer=none
b (rlc) parent= a and c d (rlc) parent = c and a
|
Go thru the above link , it should clear your doubts _________________ Anil Sarathy |
|
Back to top |
|
 |
swapna Beginner
Joined: 28 Nov 2005 Posts: 4 Topics: 1 Location: chennai
|
Posted: Fri Dec 02, 2005 12:32 am Post subject: |
|
|
Anil , thanks for the link. I am able to figure it out now. _________________ Thanks,
Swapna |
|
Back to top |
|
 |
|
|