About KGLHD function in shared pool

hwqhx

谁有关于share pool中KGLHD  function 相关的介绍？

Maclean Liu(刘相兵

KGLHD is not Function

KGL ->  Kernel Generic Library
KGLHD  Library cache Handle structure
KGLOB - Object structure
KGLNA - Name structure



KGLHD -> KGLOB
               ->  KGLNA -> KGLNA->KGLNA




Object Handles

All objects that are stored in the library cache are accessed by using handles (kglhd). The handle stores the name of the object, its namespace, some flags that are used to get information about the object (if the object is read-only, remote or local, in CGA memory, marked to be kept pinned in memory, and so on), and statistical information regarding the object. The handle is also used by the library cache to keep a list of all users who have locks, pins, or references to the object as well as those who are waiting to acquire locks or pins on it.
Object handles are placed in linked lists according to a hashing algorithm, which is a function of the object’s name and namespace.


When a process requests an object, the library cache manager applies the hashing algorithm to determine the linked list (hash bucket) to be searched. If the object is in cache, the appropriate object handle will be found. It is possible for the handle to be in memory but the object heaps have been aged out. The object handle will tell us that. In this case, the required object heaps are reloaded. Finally, it is possible that the object handle is not found. In this case, a new one must be allocated, it must be populated with the object information, and the object heaps must be loaded.


Handles: kglhd

Files kgl.c kgl2.c kgl.h

hwqhx

thanks for your help

aesthetik

非常有帮助的解释

aesthetik

nice knowledge