What are the common causes of library cache lock?

What are the common causes of library cache lock? I believe many inexperienced people don't know what to do about it. Therefore, this paper summarizes the causes and solutions of the problems. Through this article, I hope you can solve this problem.

Common causes of library cache lock

Troubleshooting Library Cache: Lock, Pin and Load Lock (Doc ID 444560.1)

It is generally understood that alter table or alter package/procedure will hold the library cache lock in X mode, causing blocking.

But there are several reasons for common problems:

1) incorrect username and password:

Generally, you need to use ASH or SSD/hang analyze to obtain p3 for namespace analysis.

1. Event: 'library cache lock'

Time waited: 43 min 12 sec

Wait id: 9 p1: 'handle address'=0x7000003117dfca0

P2: 'lock address'=0x700000310866c80

P3: '100*mode+namespace'=0x4f0003

* time between wait # 1 and # 2: 0.000164 sec

DEC: 79

Select * FROM V$DB_OBJECT_CACHE

SQL > select distinct KGLHDNSP,KGLHDNSD from x$kglob

KGLHDNSP KGLHDNSD

-

0 SQL AREA

4 INDEX

1 TABLE/PROCEDURE

3 TRIGGER

52 SCHEDULER EARLIEST START TIME

64 EDITION

69 DBLINK

2 BODY

10 QUEUE

79 ACCOUNT_STATUS

23 RULESET

24 RESOURCE MANAGER

73 SCHEMA

74 DBINSTANCE

51 SCHEDULER GLOBAL ATTRIBUTE

38 RULE EVALUATION CONTEXT

82 SQL AREA BUILD

75 SQL AREA STATS

5 CLUSTER

18 PUB SUB INTERNAL INFORMATION