以下为一份addm报告，查看该报告，可以得到addm给我们的建议，addm和awr一样，每份addm报告的格式基本一样，只是内容不同而已。

$ cat addmrpt_1_20314_20317.txt

第一部分是指出收集ADDM的时间段

ADDM Report for Task 'TASK_62667'

---------------------------------

Analysis Period

---------------

AWR snapshot range from 20314 to 20317.

Time period starts at 24-DEC-13 09.00.01 AM

Time period ends at 24-DEC-13 11.06.35 AM

第二部分是库的基本信息，主要包括版本，dbid

Analysis Target

---------------

Database 'PMSESBDB' with DB ID 1256960331.

Database version 11.1.0.6.0.

ADDM performed an analysis of instance ESBP1, numbered 1 and hosted at

PMSEBPD1.

第三部分列出db_time

Activity During the Analysis Period

-----------------------------------

Total database time was 402 seconds.

The average number of active sessions was .05.

第四部分是ADDM给出的一个大概的统计建议

Summary of Findings

-------------------

Description                     Active Sessions      Recommendations

Percent of Activity

------------------------------  -------------------  ---------------

1   Virtual Memory Paging           .05 | 100            3

2   Top SQL by DB Time              .02 | 37.8           5

3   Top SQL by "Cluster" Wait       .01 | 16.51          5

4   Commits and Rollbacks           0 | 6.91             2

5   Buffer Busy                     0 | 5.58             0

6   Interconnect Buffer Busy        0 | 4.49             1

7   Unusual "Other" Wait Event      0 | 4.01             1

8   PL/SQL Compilation              0 | 3.07             1

9   Hard Parse Due to Parse Errors  0 | 2.34             1

10  Session Connect and Disconnect  0 | 2.22             1

备注：这里由于库很闲，所以这里的百分比都不大，虚拟内存换页也才5%，topsql的dbtime为2%也不高。

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

第五部分是ADDM的详解建议

Findings and Recommendations

----------------------------

Finding 1: Virtual Memory Paging----------建议1：肯定要从第一项说起，这里第一个就是虚拟内存换页。

Impact is .05 active sessions, 100% of total activity.

------------------------------------------------------

Significant virtual memory paging was detected on the host operating system.

Recommendation 1: Host Configuration--这是给出的建议，让调整主机信息。

Estimated benefit is .05 active sessions, 100% of total activity.

-----------------------------------------------------------------

Action

Host operating system was experiencing significant paging but no

particular root cause could be detected. Investigate processes that do

not belong to this instance running on the host that are consuming

significant amount of virtual memory. Also consider adding more physical

memory to the host.

Recommendation 2: Database Configuration

Estimated benefit is .05 active sessions, 100% of total activity.

-----------------------------------------------------------------

Action

Consider enabling Automatic Shared Memory Management by setting the

parameter "sga_target" to control the amount of SGA consumed by this

instance.--让设置sga_target

Recommendation 3: Database Configuration

Estimated benefit is .05 active sessions, 100% of total activity.

-----------------------------------------------------------------

Action

Consider enabling Automatic PGA Memory Management by setting the

parameter "pga_aggregate_target" to control the amount of PGA consumed

by this instance.--让设置pga_aggregate_target

Finding 2: Top SQL by DB Time-----建议2：给出topsql，这里会将sql直接列出，比较直观

Impact is .02 active sessions, 37.8% of total activity.

-------------------------------------------------------

SQL statements consuming significant database time were found.

Recommendation 1: SQL Tuning

Estimated benefit is .01 active sessions, 15.27% of total activity.

-------------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "1rswbxwhbpmr7".

Related Object

SQL statement with SQL_ID 1rswbxwhbpmr7 and PLAN_HASH 876628497.

select decode(bitand(a.flags, 16384), 0, a.next_run_date,

a.last_enabled_tim..........................省略

Rationale

SQL statement with SQL_ID "1rswbxwhbpmr7" was executed 287 times and had

an average elapsed time of 0.21 seconds.

Recommendation 2: SQL Tuning

Estimated benefit is 0 active sessions, 7.6% of total activity.

---------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "6xfsagzmrr54f".

Related Object

SQL statement with SQL_ID 6xfsagzmrr54f and PLAN_HASH 587169518.

select * from..........................省略

Action

Investigate the SQL statement with SQL_ID "6xfsagzmrr54f" for possible

performance improvements.

Related Object

SQL statement with SQL_ID 6xfsagzmrr54f and PLAN_HASH 587169518.

select * from ..........................省略

Rationale

SQL statement with SQL_ID "6xfsagzmrr54f" was executed 1 times and had

an average elapsed time of 26 seconds.

Recommendation 3: SQL Tuning

Estimated benefit is 0 active sessions, 5.41% of total activity.

----------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "6ssrk2dqj7jbx".

Related Object

SQL statement with SQL_ID 6ssrk2dqj7jbx and PLAN_HASH 3447323253.

select ..........................省略

Rationale

SQL statement with SQL_ID "6ssrk2dqj7jbx" was executed 704 times and had

an average elapsed time of 0.03 seconds.

Recommendation 4: SQL Tuning

Estimated benefit is 0 active sessions, 5.19% of total activity.

----------------------------------------------------------------

Action

Tune the PL/SQL block with SQL_ID "5471z2mmaf89k". Refer to the "Tuning

PL/SQL Applications" chapter of Oracle's "PL/SQL User's Guide and--让看书自己调优

Reference".

Related Object

SQL statement with SQL_ID 5471z2mmaf89k.

BEGIN ..........................省略

Rationale

SQL statement with SQL_ID "5471z2mmaf89k" was executed 83 times and had

an average elapsed time of 0.27 seconds.

Recommendation 5: SQL Tuning

Estimated benefit is 0 active sessions, 5.17% of total activity.

----------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "18naypzfmabd6".

Related Object

SQL statement with SQL_ID 18naypzfmabd6.

INSERT INTO ..........................省略

Rationale

SQL statement with SQL_ID "18naypzfmabd6" was executed 513 times and had

an average elapsed time of 0.04 seconds.

Finding 3: Top SQL by "Cluster" Wait---给出一些发生内存间传递的sql

Impact is .01 active sessions, 16.51% of total activity.

--------------------------------------------------------

SQL statements responsible for significant inter-instance messaging were

found.

Recommendation 1: SQL Tuning

Estimated benefit is 0 active sessions, 7.6% of total activity.

---------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "6xfsagzmrr54f".

Related Object

SQL statement with SQL_ID 6xfsagzmrr54f and PLAN_HASH 587169518.

select * from ..........................省略

Action

Investigate the SQL statement with SQL_ID "6xfsagzmrr54f" for possible

performance improvements.

Related Object

SQL statement with SQL_ID 6xfsagzmrr54f and PLAN_HASH 587169518.

select * from..........................省略

Rationale

SQL statement with SQL_ID "6xfsagzmrr54f" was executed 1 times and had

an average elapsed time of 26 seconds.

Rationale

Average time spent in Cluster wait events per execution was 2.8 seconds.

Recommendation 2: SQL Tuning

Estimated benefit is 0 active sessions, 5.41% of total activity.

----------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "6ssrk2dqj7jbx".

Related Object

SQL statement with SQL_ID 6ssrk2dqj7jbx and PLAN_HASH 3447323253.

select ..........................省略

Rationale

SQL statement with SQL_ID "6ssrk2dqj7jbx" was executed 704 times and had

an average elapsed time of 0.03 seconds.

Rationale

Average time spent in Cluster wait events per execution was 0.03

seconds.

Recommendation 3: SQL Tuning

Estimated benefit is 0 active sessions, 5.17% of total activity.

----------------------------------------------------------------

Action

Run SQL Tuning Advisor on the SQL statement with SQL_ID "18naypzfmabd6".

Related Object

SQL statement with SQL_ID 18naypzfmabd6.

INSERT INTO ..........................省略

Rationale

SQL statement with SQL_ID "18naypzfmabd6" was executed 513 times and had

an average elapsed time of 0.04 seconds.

Rationale

Average time spent in Cluster wait events per execution was 0.04

seconds.

Recommendation 4: SQL Tuning

Estimated benefit is 0 active sessions, 5.14% of total activity.

----------------------------------------------------------------

Action

Tune the PL/SQL block with SQL_ID "5471z2mmaf89k". Refer to the "Tuning

PL/SQL Applications" chapter of Oracle's "PL/SQL User's Guide and

Reference".

Related Object

SQL statement with SQL_ID 5471z2mmaf89k.

BEGIN ..........................省略

Rationale

SQL statement with SQL_ID "5471z2mmaf89k" was executed 83 times and had

an average elapsed time of 0.27 seconds.

Rationale

Average time spent in Cluster wait events per execution was 0.24

seconds.

Recommendation 5: SQL Tuning

Estimated benefit is 0 active sessions, .16% of total activity.

---------------------------------------------------------------

Action

Tune the PL/SQL block with SQL_ID "6gvch1xu9ca3g". Refer to the "Tuning

PL/SQL Applications" chapter of Oracle's "PL/SQL User's Guide and

Reference".

Related Object

SQL statement with SQL_ID 6gvch1xu9ca3g.

DECLARE ..........................省略

Rationale

SQL statement with SQL_ID "6gvch1xu9ca3g" was executed 90 times and had

an average elapsed time of 0.13 seconds.

Rationale

Average time spent in Cluster wait events per execution was 0.0071

seconds.

Symptoms That Led to the Finding:

---------------------------------

Wait class "Cluster" was consuming significant database time.

Impact is 0 active sessions, 7.31% of total activity.

Finding 4: Commits and Rollbacks----发现4，提交和回退

Impact is 0 active sessions, 6.91% of total activity.有6.9%的dbtime消耗在此，会产生logfilesync等待事件。

-----------------------------------------------------

Waits on event "log file sync" while performing COMMIT and ROLLBACK operations

were consuming significant database time.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 6.91% of total activity.

----------------------------------------------------------------

Action

Investigate application logic for possible reduction in the number of

COMMIT operations by increasing the size of transactions.

Rationale

The application was performing 31 transactions per minute with an

average redo size of 10064 bytes per transaction.

Recommendation 2: Host Configuration

Estimated benefit is 0 active sessions, 6.91% of total activity.

----------------------------------------------------------------

Action

Investigate the possibility of improving the performance of I/O to the

online redo log files.

Rationale

The average size of writes to the online redo log files was 7 K and the

average time per write was 4 milliseconds.

Symptoms That Led to the Finding:

---------------------------------

Wait class "Commit" was consuming significant database time.

Impact is 0 active sessions, 6.91% of total activity.

Finding 5: Buffer Busy

Impact is 0 active sessions, 5.58% of total activity.

-----------------------------------------------------

Read and write contention on database blocks was consuming significant

database time. However, no single object was the predominant cause for this

contention.

No recommendations are available.

Symptoms That Led to the Finding:

---------------------------------

Inter-instance messaging was consuming significant database time on this

instance.

Impact is 0 active sessions, 7.29% of total activity.

Wait class "Cluster" was consuming significant database time.

Impact is 0 active sessions, 7.31% of total activity.

Finding 6: Interconnect Buffer Busy

Impact is 0 active sessions, 4.49% of total activity.

-----------------------------------------------------

Read and write contention on database blocks was consuming significant

database time in the cluster.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 4.49% of total activity.

----------------------------------------------------------------

Action

Verify that the set of services used by the application to connect to

the database are optimally distributed if response time is critical.

Symptoms That Led to the Finding:

---------------------------------

Inter-instance messaging was consuming significant database time on this

instance.

Impact is 0 active sessions, 7.29% of total activity.

Wait class "Cluster" was consuming significant database time.

Impact is 0 active sessions, 7.31% of total activity.

Finding 7: Unusual "Other" Wait Event

Impact is 0 active sessions, 4.01% of total activity.

-----------------------------------------------------

Wait event "reliable message" in wait class "Other" was consuming significant

database time.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 4.01% of total activity.

----------------------------------------------------------------

Action

Investigate the cause for high "reliable message" waits. Refer to

Oracle's "Database Reference" for the description of this wait event.

Symptoms That Led to the Finding:

---------------------------------

Wait class "Other" was consuming significant database time.

Impact is 0 active sessions, 7.78% of total activity.

Finding 8: PL/SQL Compilation

Impact is 0 active sessions, 3.07% of total activity.

-----------------------------------------------------

PL/SQL compilation consumed significant database time.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 3.07% of total activity.

----------------------------------------------------------------

Action

Investigate the appropriateness of PL/SQL compilation. PL/SQL

compilation can be caused by DDL on dependent objects.

Finding 9: Hard Parse Due to Parse Errors

Impact is 0 active sessions, 2.34% of total activity.

-----------------------------------------------------

Hard parsing SQL statements that encountered parse errors was consuming

significant database time.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 2.34% of total activity.

----------------------------------------------------------------

Action

Investigate application logic to eliminate parse errors.

Symptoms That Led to the Finding:

---------------------------------

Hard parsing of SQL statements was consuming significant database time.

Impact is 0 active sessions, 3.99% of total activity.

Finding 10: Session Connect and Disconnect

Impact is 0 active sessions, 2.22% of total activity.

-----------------------------------------------------

Session connect and disconnect calls were consuming significant database time.

Recommendation 1: Application Analysis

Estimated benefit is 0 active sessions, 2.22% of total activity.

----------------------------------------------------------------

Action

Investigate application logic for possible reduction of connect and

disconnect calls. For example, you might use a connection pool scheme in

the middle tier.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Additional Information

----------------------

Miscellaneous Information

-------------------------

Wait class "Application" was not consuming significant database time.

Wait class "Concurrency" was not consuming significant database time.

Wait class "Configuration" was not consuming significant database time.

CPU was not a bottleneck for the instance.

Wait class "Network" was not consuming significant database time.

Wait class "User I/O" was not consuming significant database time.

The network latency of the cluster interconnect was within acceptable limits

of 1 milliseconds.