...

*.Relationshin between:
                      KGLHD - Handle structure   
                      KGLOB - Object structure 
                      KGLNA - Name structure   
   
                                       |-------|
                                       | KGLHD |
                                       --------|
                                       /       \
                                      /         \
                                  |-----|      |-----|                                                --可以说明一个Parent Cursor可以包含多个KGL NAme
                                  |KGLOB|      |KGLNA|\  (-child cur?)
                                  |-----|      ------- \
                                                  |     \
                                               |-----|   \ SQL="
                                               |KGLNA|    |SELECT c1,c2,c3,c4,c5,c6,c7,c8,c9,c10 
                                               -------   / FROM t1,t2, t3,t4,t5                  
                                                  |     /  WHERE t1.c1=t2.c1..  "                 
                                               |-----| /
                                               |KGLNA|/
  ...

 

 

4.Child Cursor Structure
Child Cur和Parent Cur区别是:
Parent的KGLHD OBJ是一定的,KGLNA(name,namspace)有派生;
Child的KGLNA(name,namespace),一定,对KGLOB(object)的派生,因为一条Sql语句包含多个子child cur,或者说一条Sql语句可以涉及多个OBJECT,因此在KGLHD在KGLOB上的派生
(i)Child cur
                                               Child Cursor
                                                ----------
                                                |  KGLHD |
                                                ----------
                                                /        \
                                               /          \
                                          ----------    ----------
                                          |  KGLOB |    |  KGLNA |
                                          ----------    ----------
                                              |
                                           Srtuct        
                                         |------|--------------------------------------------------
                                         |------|                                                 |
                                         |------|                                                 |Struct
                                         |------|                                              |------|
                                             |                                                 |------|
                                             |                                                 |------|--------|
                                             |Struct                                |----------|------|        |
                         |---------------|------|                                   |          |------|        |
                         |               |------|                                   |          |------|     -------
                      |-----|            |------|----------------------          |-----|                    |KGLHD|
                      |KGLHD|            |------|-----------          |          |KGLHD|                    |-----|
                      |-----|                              |          |          |-----|
                                                       |-----|      |-----| 
                                                       |KGLHD|      |KGLHD|                    
                                                       |-----|      |-----|
                           
(ii)Heap and Child Cursor                         
                      
                                     
                                     
                                        Child Cursor          
                                         ----------          
                                         |  KGLHD |          
                                         ----------          
                                             |
                                         ----------  
                                         |  KGLOB | 
                                         ---------- 
                                        /          \  
                                       /            \
                                      /              \
                                -----------            ----------
                                | Heap0   |            |  Heap6 |                 -Heap6 context,Child plus Exection plan
                                -----------            ----------
                               /     |     \               |
                              /      |      \          -----------  
                             /       |       \         | Execution|
                            /        |        \        | Plan     |
                ------------| -----------||---------|  ------------ 
                |Enviroment | |Statistics||  Bind   |
                |           | |          ||Variables|
                ------------  ----------- -----------