What is the v$resource in 10g??

Question

Hi, all.
What is the v$resource in 10g??
The folloing link is not sufficient to understand.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/dynviews_2049.htm#sthref3892
Is there anyone who could provide me with a little more details??
Thanks and Regards.
Message was edited by:
user507290

Answer 1

This is somewhat internal view, which means you don't need to know in detail.
Anyway, see following:
SQL> SELECT view_definition FROM v$fixed_view_definition
where view_name = 'GV$RESOURCE';
==>
select inst_id,addr,ksqrsidt,ksqrsid1,ksqrsid2 from x$ksqrs where bitand(ksqrsflg,2)!=0
The base x$ table is x$ksqrs, which means "enqueue resource".
To understand this, you need to be familiar with some terminologies.
- enqueue lock: special type of lock. sometimes called just "enqueue".
- enqueue resources: resources which are protected by enqueue lock.
Enqueue resource is identifed by following info:
resource type(2) + resource identifer1 + resource identifier2
For instance, a table whose id is 1000 is represented as [TM+1000+0]. A sequence whose id is 888 is represented as [SQ+888+0].
Every resource which is protected by enqueue lock is exposed via V$RESOURCE view. And equeue lock is exposed exposed via V$LOCK view. The relationship between V$RESOURCE and V$LOCK is 1:m. For instance, let's assume that table 1000 is locked by session 1 in exclusive mode, and session 2 is waiting to lock the same table in exclusive mode. In this case, one record(TM+1000+0) is registered in V$RESOURCE view, and two records(one blocker+one blockee) are registered in V$LOCK view.
You need to google "Oracle enqueue resource" or something.
Hope this helps.
PS) 99% of locks in Oracle are "enqueue lock", which are exposed via V$RESOURCE and V$LOCK view. But some locks are not exposed by these views. For instance, library cache lock is exposed via X$KGLLK, library cache pin is exposed via X$KGLPN.