实验第21步：

在任一个实例上执行:

selectcount(*)from myviewwhere "OWNER_Instance" <> "MASTER_Instance"  ;

COUNT(*)

1239

从以上结果可以看到，存在大量的数据块的master实例和owner实例不是同一个实例的情况。这是可以预料到的：我们在两个实例上同时密集地OLTP同一张表！这样会有大量的实例间的通信。以下内容来自此刻的AWR报告：

Top  5 Timed EventsEventWaitsTime(s)Avg Wait(ms)% Total Call TimeWait Class

gc cr block busy85,181181244.5Cluster←对方CR块请求收到，但是无法立即发送

CPU time7919.4

gcs log flush sync37,3493518.6Other←日志系统太满flush不过来

gc cr multi block request1,62327166.5Cluster← placeholder请求多

gc current    grant busy13,1622025.0Cluster←由于master实例和owner实例不是同一个实例导致master实例发送磁盘授权信息延迟或接收延迟。

RAC  Statistics

BeginEnd

Number of Instances:22

Global  Cache Load Profile

Per SecondPer Transaction

Global Cache blocks    received:264.261,108.00

Global Cache blocks    served:356.691,495.53

GCS/GES messages received:452.071,895.44

GCS/GES    messages sent:462.241,938.10

DBWR Fusion writes:0.160.67

Estd Interconnect traffic    (KB)5,146.16

Global  Cache Efficiency Percentages (Target local+remote 100%)

Buffer  access - local cache %:99.69

Buffer  access - remote cache %:0.30

Buffer  access - disk %:0.00

Global  Cache and Enqueue Services - Workload Characteristics

Avg  global enqueue get time (ms):0.3

Avg  global cache cr block receive time (ms):2.0

Avg  global cache current block receive time (ms):1.4

Avg  global cache cr block build time (ms):0.1

Avg  global cache cr block send time (ms):0.0

Global  cache log flushes for cr blocks served %:23.9

Avg  global cache cr block flush time (ms):1.5

Avg  global cache current block pin time (ms):0.0

Avg  global cache current block send time (ms):0.0

Global  cache log flushes for current blocks served %:0.2

Avg  global cache current block flush time (ms):1.9

Global  Cache and Enqueue Services - Messaging Statistics

Avg message sent queue time (ms):0.2

Avg  message sent queue time on ksxp (ms):0.8

Avg  message received queue time (ms):0.0

Avg  GCS message process time (ms):0.1

Avg  GES message process time (ms):0.0

%  of direct sent messages:73.86

%  of indirect sent messages:13.11

%  of flow controlled messages:13.03