library cache: mutex X

发现数据库存在 ;library cache: mutex X 等待事件 （ID 1357946.1）

Top 5 Timed Foreground Events

Event	Waits	Time(s)	Avg wait (ms)	% DB time	Wait Class
library cache: mutex X	41,542	29,458	709	21.04	Concurrency
latch: shared pool	2,555	7,568	2962	5.40	Concurrency
enq: TX - index contention	3,116	3,686	1183	2.63	Concurrency
DB CPU		2,672		1.91
SQL*Net message from dblink	4,402,415	1,227	0	0.88	Network

下面我们通过awr 报告来进行诊断：

1、First look for high parsing and high version counts from AWR.

SQL ordered by Parse Calls

• Total Parse Calls: 171,846
• Captured SQL account for 26.8% of Total

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Parse Calls	Executions	% Total Parses	SQL Id	SQL Module	SQL Text
3,532	7,853	2.06	cm5vu20fhtnq1		select /*+ connect_by_filterin...
3,527	3,531	2.05	0k8522rmdzg4k		select privilege# from sysauth...
3,516	3,517