透過ADDM進行SQL調優

declare
l_task_id varchar2(20);
l_sql varchar2(2000);
begin
l_sql := 'SELECT COUNT(*) QTY FROM SFCS_DEFECTS WHERE ORG_ID=:1 AND SN_KEY=:2 and rs_id is null';
dbms_sqltune.drop_tuning_task ('addm');
l_task_id := dbms_sqltune.create_tuning_task (
sql_text => l_sql,
user_name => 'SMP',
scope => 'COMPREHENSIVE',
time_limit => 120,
task_name => 'addm'
);
dbms_sqltune.execute_tuning_task ('addm');
end;
/

set serveroutput on size 999999
set long 999999
select dbms_sqltune.report_tuning_task ('addm') from dual;[@more@]

實際操作如下：


#################
addm report:
#################

Running the ADDM analysis on the specified pair of snapshots ...


Generating the ADDM report for this analysis ...


DETAILED ADDM REPORT FOR TASK 'TASK_24828' WITH ID 24828
--------------------------------------------------------

Analysis Period: 26-OCT-2010 from 09:00:50 to 10:00:48
Database ID/Instance: 774218943/1
Database/Instance Names: STCSMES/STCSMES
Host Name: stcsmesfab2
Database Version: 10.2.0.4.0
Snapshot Range: from 5399 to 5400
Database Time: 45103 seconds
Average Database Load: 12.5 active sessions

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


FINDING 1: 72% impact (32345 seconds)
-------------------------------------
Host CPU was a bottleneck and the instance was consuming 47% of the host CPU.
All wait times will be inflated by wait for CPU.

RECOMMENDATION 1: Host Configuration, 58% benefit (26237 seconds)
ACTION: Consider adding more CPUs to the host or adding instances
serving the database on other hosts.
ACTION: Also consider using Oracle Database Resource Manager to
prioritize the workload from various consumer groups.

RECOMMENDATION 2: SQL Tuning, 23% benefit (10494 seconds)
ACTION: Run SQL Tuning Advisor on the SQL statement with SQL_ID
"6u2js5kw4v66k".
RELEVANT OBJECT: SQL statement with SQL_ID 6u2js5kw4v66k and
PLAN_HASH 2068937292
select count(*) cnt from(select sn_key,i_time from SFCS_DEFECTS where
org_id=:1 and sn_key=:2 and rs_id is null group by sn_key,i_time)
ACTION: Investigate the SQL statement with SQL_ID "6u2js5kw4v66k" for
possible performance improvements.
RELEVANT OBJECT: SQL statement with SQL_ID 6u2js5kw4v66k and
PLAN_HASH 2068937292
select count(*) cnt from(select sn_key,i_time from SFCS_DEFECTS where
org_id=:1 and sn_key=:2 and rs_id is null group by sn_key,i_time)
RATIONALE: SQL statement with SQL_ID "6u2js5kw4v66k" was executed 15735
times and had an average elapsed time of 0.65 seconds.
RATIONALE: Average CPU used per execution was 0.26 seconds.

##########################
透過addm進行SQL調優：
##########################

SQL> declare
2 l_task_id varchar2(20);
3 l_sql varchar2(2000);
4 begin
5 l_sql := 'select count(*) cnt from(select sn_key, i_time from SFCS_DEFECTS where org_id=:1 and sn_key=:2 and rs_id is null group by sn_key, i_time)';
6 l_task_id := dbms_sqltune.create_tuning_task (
7 sql_text => l_sql,
8 user_name => 'SMP',
9 scope => 'COMPREHENSIVE',
10 time_limit => 60,
11 task_name => 'addm'
12 );
13 dbms_sqltune.execute_tuning_task ('addm');
14 end;
15 /

PL/SQL procedure successfully completed.

SQL> set serveroutput on size 999999
SQL> set long 999999
SQL> select dbms_sqltune.report_tuning_task ('addm') from dual;

DBMS_SQLTUNE.REPORT_TUNING_TASK('ADDM')
--------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name : addm
Tuning Task Owner : SYS
Scope : COMPREHENSIVE
Time Limit(seconds): 60
Completion Status : COMPLETED
Started at : 10/26/2010 13:41:10
Completed at : 10/26/2010 13:41:14

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

DBMS_SQLTUNE.REPORT_TUNING_TASK('ADDM')
--------------------------------------------------------------------------------
Schema Name: SMP
SQL ID : 78nrgfjx0qkkv
SQL Text : select count(*) cnt from(select sn_key, i_time from SFCS_DEFECTS
where org_id=:1 and sn_key=:2 and rs_id is null group by sn_key,
i_time)

-------------------------------------------------------------------------------
There are no recommendations to improve the statement.

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

參考網址：

%2010G_addm_advisor.htm

http://space.itpub.net/?uid-12361284-action-viewspace-itemid-164945