library cache lock
This event controls the concurrency between clients of the library cache. It acquires a lock on the object handle so that either:
- One client can prevent other clients from accessing the same object.
- The client can maintain a dependency for a long time (for example, no other client can change the object).
This lock is also obtained to locate an object in the library cache. Wait Time:
3 seconds (1 second for PMON)
|
Parameter |
Description |
|---|---|
|
handle address |
Address of the object being loaded |
|
lock address |
Address of the load lock being used. This is not the same thingas a latch or an enqueue, it is a State Object. |
|
Mode |
Indicates the data pieces of the object which need to be loaded |
|
namespace |
namespace |
Oracle tries to find the load lock for the database object so that it can load the object. The load lock is always gotten in Exclusive mode, so that no other process can load the same object. If the load lock is busy, the session will wait on this event until the lock becomes available.
|
Mask |
Meaning |
|---|---|
|
0x01 |
object/ datablock 0, object |
|
0x02 |
data block 1, source |
|
0x04 |
data block 2, diana |
|
0x08 |
data block 3, pcode |
|
0x10 |
data block 4, machine-dependent pcode |
|
0x20 |
data block 5, error |
|
0x40 |
data block 6, SQL context (cursor) |
|
0x80 |
data block 7 |
namespace
|
Namespace |
Meaning |
|---|---|
|
0 |
Cursor |
|
1 |
table/view/sequence/synonym/class/set/procedure/function/package |
|
2 |
body (e.g. package body) |
|
3 |
trigger |
|
4 |
index |
|
5 |
cluster |
|
6 |
object |
|
7 |
pipe |
|
127 |
no namespace |