Oracle adviser,Oracle10g SQL tune adviser
Oracle10g SQL tune adviser簡(jiǎn)單介紹
本文簡(jiǎn)單介紹下SQL Tuning Adviser的配置使用方法和一些相關(guān)知識(shí)點(diǎn)，如果了解SQL Tuning Adviser詳細(xì)信息，參看Oracle聯(lián)機(jī)文檔。本文對(duì)分析結(jié)果沒(méi)有詳細(xì)分析。
一、自動(dòng)SQL Tuning簡(jiǎn)單介紹：
1、優(yōu)化模式：
10G增強(qiáng)的優(yōu)化模式有兩種：
a、Normal mode
在普通優(yōu)化模式下，優(yōu)化器編譯sql然后產(chǎn)生執(zhí)行計(jì)劃。普通優(yōu)化模式下優(yōu)化器能夠快速的為sql語(yǔ)句產(chǎn)生可行的執(zhí)行計(jì)劃。
b、Tuning mode
在tuning mode模式下，優(yōu)化器將花費(fèi)額外的時(shí)間檢查一個(gè)普通模式下產(chǎn)生的執(zhí)行計(jì)劃是否可以優(yōu)化。優(yōu)化器的輸出結(jié)果將不僅僅是產(chǎn)生一個(gè)執(zhí)行計(jì)劃，
而將執(zhí)行一系列的動(dòng)作，在該模式下優(yōu)化器也許化肥幾分鐘去調(diào)整一個(gè)語(yǔ)句。每次一個(gè)sql語(yǔ)句被硬解析后將在自動(dòng)調(diào)整優(yōu)化上花費(fèi)更多的時(shí)間和資源。
sql自動(dòng)調(diào)整優(yōu)化更適用于有復(fù)雜sql或者h(yuǎn)igh-load sql的系統(tǒng)(例如addm中標(biāo)記為高負(fù)載的sql就非常適合作為sql自動(dòng)調(diào)整的目標(biāo))。
2、? ? ? ? SQL Tuning類(lèi)型
Automatic SQL Tuning包含四種類(lèi)型的分析:
a、Statistics Analysis
b、SQL Profiling
c、Access Path Analysis
d、SQL Structure Analysis
二、SQL Tuning Adviser：
1、授予用戶相應(yīng)權(quán)限：
CONN sys/password AS SYSDBA
GRANT ADVISOR TO TEST;
CONN TEST/TEST
2、創(chuàng)建Tuning任務(wù)：
可以通過(guò)以下方式創(chuàng)建Tuning任務(wù)：
a、Automatic Workload Repository (AWR)
b、the cursor cache
c、SQL tuning set
d、specified manually
SET SERVEROUTPUT ON
--a、通過(guò)AWR設(shè)置Tuning任務(wù).
SQL> conn /as sysdba
已連接。
--查看AWR的SNAPSHOT信息：
SQL> SELECT max(snap_id) FROM WRM$_SNAPSHOT;
MAX(SNAP_ID)
------------
201
--查看SNAP間隔：
SQL> select snap_interval, retention from dba_hist_wr_control;
SNAP_INTERVAL? ?? ?? ?? ?? ?? ?RETENTION
------------------------------ ------------------------------
+00000 01:00:00.0? ?? ?? ?? ???+00007 00:00:00.0
--我們可以手工縮短AWR采樣時(shí)間間隔(加快測(cè)試速度，本利采用手工執(zhí)行創(chuàng)建SNAPSHOT的方法)：
begin
dbms_workload_repository.modify_snapshot_settings (
interval => 10,
retention => 10*24*60
);
end;
SQL> conn test/test
已連接。
--執(zhí)行目標(biāo)SQL：
SQL> select /*We will trace this sql*/ name,addr,insertdata from (select name,ad
dr,insertdata,rank() over(partition by name,addr order by insertdata desc) rn fr
om t ) where rn = 1;
NAME? ?? ? ADDR? ?? ?? ?? ?? ???INSERTDATA
---------- -------------------- -------------------
王? ?? ?? ?上海? ?? ?? ?? ?? ???19-12-2006 10:09:33
王1? ?? ???上海? ?? ?? ?? ?? ???16-12-2006 10:11:15
王2? ?? ???上海? ?? ?? ?? ?? ???16-12-2006 10:11:15
張? ?? ?? ?北京? ?? ?? ?? ?? ???19-12-2006 10:08:42
--查找SQL_ID：
SQL> select sql_id,executions from v$sqlarea where lower(sql_text) like '%we wil
l trace this sql%';
SQL_ID? ?? ???EXECUTIONS
------------- ----------
8zu31x4adn76f? ?? ?? ? 1
1k659753fzcxn? ?? ?? ? 1
SQL> /
SQL_ID? ?? ???EXECUTIONS
------------- ----------
8zu31x4adn76f? ?? ?? ? 2
1k659753fzcxn? ?? ?? ? 1? ?--我們將分析該SQL
SQL> select sql_id from DBA_HIST_SQLSTAT where sql_id='1k659753fzcxn';
未選定行
--手工創(chuàng)建新的AWR SNAPSHOT：
SQL> execute dbms_workload_repository.create_snapshot;
PL/SQL 過(guò)程已成功完成。
SQL> select sql_id from DBA_HIST_SQLSTAT where sql_id='1k659753fzcxn';
SQL_ID
-------------
1k659753fzcxn
--創(chuàng)建Tuning task：
SQL> DECLARE
2? ?? ?? ?? ?? ?l_sql_tune_task_id??VARCHAR2(100);
3? ?? ?? ?? ? BEGIN
4? ?? ?? ?? ?? ?l_sql_tune_task_id := DBMS_SQLTUNE.create_tuning_task (
5? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?begin_snap??=> 201,
6? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?end_snap? ? => 202,
7? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?sql_id? ?? ?=> '1k659753fzcxn',
8? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?scope? ?? ? => DBMS_SQLTUNE.scope_comprehensive,
9? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?time_limit??=> 60,
10? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?task_name? ?=> '1k659753fzcxn_awr_tuning_task',
11? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?description => 'Tuning task for statement 1k659753fzcxn in AWR.');
12? ?? ?? ?? ?? ?DBMS_OUTPUT.put_line('l_sql_tune_task_id: ' || l_sql_tune_task_id);
13? ?? ?? ?? ? END;
14??/
PL/SQL 過(guò)程已成功完成。
SQL> SELECT task_name, status FROM dba_advisor_log WHERE owner = 'TEST';
TASK_NAME? ?? ?? ?? ?? ?? ?? ? STATUS
------------------------------ -----------
ADDM:1184202927_1_201? ?? ?? ? COMPLETED
ADDM:1184202927_1_202? ?? ?? ? COMPLETED
1k659753fzcxn_awr_tuning_task??INITIAL
--執(zhí)行Tuning task：
SQL> EXEC DBMS_SQLTUNE.execute_tuning_task(task_name => '1k659753fzcxn_awr_tuning_task');
PL/SQL 過(guò)程已成功完成。
SQL> SET LONG 999999;
SQL> SET PAGESIZE 1000
SQL> SET LINESIZE 200
--查看Tuning advice：
SQL> SELECT DBMS_SQLTUNE.report_tuning_task('1k659753fzcxn_awr_tuning_task') AS recommendations FROM dual;
RECOMMENDATIONS
--------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name? ?? ?? ?? ?? ?? ?: 1k659753fzcxn_awr_tuning_task
Tuning Task Owner? ?? ?? ?? ?? ???: TEST
Scope? ?? ?? ?? ?? ?? ?? ?? ?? ???: COMPREHENSIVE
Time Limit(seconds)? ?? ?? ?? ?? ?: 60
Completion Status? ?? ?? ?? ?? ???: COMPLETED
Started at? ?? ?? ?? ?? ?? ?? ?? ?: 07/09/2008 22:40:27
Completed at? ?? ?? ?? ?? ?? ?? ? : 07/09/2008 22:40:28
-------------------------------------------------------------------------------
Schema Name: TEST
SQL ID? ???: 1k659753fzcxn
SQL Text? ?: select /*We will trace this sql*/ name,addr,insertdata from
(select name,addr,insertdata,rank() over(partition by name,addr
order by insertdata desc) rn from t ) where rn = 1
-------------------------------------------------------------------------------
ADDITIONAL INFORMATION SECTION
-------------------------------------------------------------------------------
-優(yōu)化程序不能合并位于執(zhí)行計(jì)劃的行 ID 1 處的視圖。.
-------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
-------------------------------------------------------------------------------
1- Original
-----------
Plan hash value: 3047187157
--------------------------------------------------------------------------------
-
| Id??| Operation? ?? ?? ?? ?? ? | Name | Rows??| Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
-
|? ?0 | SELECT STATEMENT? ?? ?? ?|? ?? ?|? ???8 |? ?368 |? ???4??(25)| 00:00:01
|
|*??1 |??VIEW? ?? ?? ?? ?? ?? ???|? ?? ?|? ???8 |? ?368 |? ???4??(25)| 00:00:01
|
|*??2 |? ?WINDOW SORT PUSHED RANK|? ?? ?|? ???8 |? ?136 |? ???4??(25)| 00:00:01
|
|? ?3 |? ? TABLE ACCESS FULL? ???| T? ? |? ???8 |? ?136 |? ???3? ?(0)| 00:00:01
|
--------------------------------------------------------------------------------
-
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("RN"=1)
2 - filter(RANK() OVER ( PARTITION BY "NAME","ADDR" ORDER BY
INTERNAL_FUNCTION("INSERTDATA") DESC )<=1)
-------------------------------------------------------------------------------
--中斷Tuning task：
EXEC DBMS_SQLTUNE.interrupt_tuning_task (task_name => '1k659753fzcxn_awr_tuning_task');
--繼續(xù)Tuning task：
EXEC DBMS_SQLTUNE.resume_tuning_task (task_name => '1k659753fzcxn_awr_tuning_task');
--取消Tuning task：
EXEC DBMS_SQLTUNE.cancel_tuning_task (task_name => '1k659753fzcxn_awr_tuning_task');
--重置Tuning task：
SQL> SELECT task_name, status FROM dba_advisor_log WHERE owner = 'TEST';
TASK_NAME? ?? ?? ?? ?? ?? ?? ? STATUS
------------------------------ -----------
ADDM:1184202927_1_201? ?? ?? ? COMPLETED
ADDM:1184202927_1_202? ?? ?? ? COMPLETED
1k659753fzcxn_awr_tuning_task??COMPLETED
SQL> EXEC DBMS_SQLTUNE.reset_tuning_task (task_name => '1k659753fzcxn_awr_tuning_task');
PL/SQL 過(guò)程已成功完成。
SQL> SELECT task_name, status FROM dba_advisor_log WHERE owner = 'TEST';
TASK_NAME? ?? ?? ?? ?? ?? ?? ? STATUS
------------------------------ -----------
ADDM:1184202927_1_201? ?? ?? ? COMPLETED
ADDM:1184202927_1_202? ?? ?? ? COMPLETED
1k659753fzcxn_awr_tuning_task??INITIAL
--刪除Tuning task：
SQL> BEGIN
2? ? DBMS_SQLTUNE.drop_tuning_task (task_name => '1k659753fzcxn_awr_tuning_task');
3??END;
4??/
PL/SQL 過(guò)程已成功完成。
SQL> SELECT task_name, status FROM dba_advisor_log WHERE owner = 'TEST';
TASK_NAME? ?? ?? ?? ?? ?? ?? ? STATUS
------------------------------ -----------
ADDM:1184202927_1_201? ?? ?? ? COMPLETED
ADDM:1184202927_1_202? ?? ?? ? COMPLETED
--b、通過(guò)cursor cache設(shè)置Tuning任務(wù).
--方法大致如下，這里我們就不再另外舉例了。
DECLARE
l_sql_tune_task_id??VARCHAR2(100);
BEGIN
l_sql_tune_task_id := DBMS_SQLTUNE.create_tuning_task (
sql_id? ?? ?=> '1k659753fzcxn',
scope? ?? ? => DBMS_SQLTUNE.scope_comprehensive,
time_limit??=> 60,
task_name? ?=> '1k659753fzcxn_tuning_task',
description => 'Tuning task for statement 1k659753fzcxn.');
DBMS_OUTPUT.put_line('l_sql_tune_task_id: ' || l_sql_tune_task_id);
END;
/
--c、通過(guò)SQL tuning set設(shè)置Tuning任務(wù).
我們可以創(chuàng)建調(diào)整SQL的集合：
SQL> CONN /AS SYSDBA
已連接。
SQL> GRANT ADMINISTER ANY SQL TUNING SET TO TEST;
授權(quán)成功。
SQL> CONN TEST/TEST
已連接。
SQL> BEGIN
2? ? DBMS_SQLTUNE.create_sqlset (
3? ?? ?sqlset_name??=> 'test_sql_tuning_set',
4? ?? ?description??=> 'A test SQL tuning set.');
5??END;
6??/
PL/SQL 過(guò)程已成功完成。
SQL> SELECT OWNER,NAME FROM DBA_SQLSET;
OWNER? ?? ?? ?? ?? ?? ?? ?? ???NAME
------------------------------ ------------------------------
TEST? ?? ?? ?? ?? ?? ?? ?? ?? ?test_sql_tuning_set
SQL> declare
2? ???cur dbms_sqltune.sqlset_cursor;
3??begin
4? ???open cur for select value(p) from table(dbms_sqltune.select_cursor_cache('parsing_schema_name = ''TEST'' ',null,null,null,null,1,null,'ALL')) P;
5? ???dbms_sqltune.load_sqlset(sqlset_name=>'test_sql_tuning_set',populate_cursor=>cur);
6??end;
7??/
PL/SQL 過(guò)程已成功完成。
SQL> select count(*) from table(dbms_sqltune.select_sqlset('test_sql_tuning_set'
, 'parsing_schema_name = ''TEST'' '));
COUNT(*)
----------
17
SQL> declare
2? ???my_task_name varchar2(30);
3??begin
4? ???my_task_name := dbms_sqltune.create_tuning_task(sqlset_name=>'test_sql_tuning_set',
5? ???time_limit=>600,
6? ???scope=>'COMPREHENSIVE',
7? ???task_name=>'test_tuning_task',
8? ???description=>'test tuning task');
9??end;
10??/
PL/SQL 過(guò)程已成功完成。
SQL> begin
2? ???dbms_sqltune.set_tuning_task_parameter(
3? ???task_name=> 'test_tuning_task',
4? ???parameter => 'TIME_LIMIT',
5? ???value=>800);
6??end;
7??/
PL/SQL 過(guò)程已成功完成。
SQL> exec dbms_sqltune.execute_tuning_task(task_name => 'test_tuning_task');
PL/SQL 過(guò)程已成功完成。
SQL> set long 999999
SQL> set longchunksize 1000
SQL> set linesize 200
SQL> select dbms_sqltune.report_tuning_task('test_tuning_task') from dual;
DBMS_SQLTUNE.REPORT_TUNING_TASK('TEST_TUNING_TASK')
-------------------------------------------------------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name? ?? ?? ?? ?? ?? ?: test_tuning_task
Tuning Task Owner? ?? ?? ?? ?? ???: TEST
Scope? ?? ?? ?? ?? ?? ?? ?? ?? ???: COMPREHENSIVE
Time Limit(seconds)? ?? ?? ?? ?? ?: 800
Completion Status? ?? ?? ?? ?? ???: COMPLETED
Started at? ?? ?? ?? ?? ?? ?? ?? ?: 07/10/2008 12:38:55
Completed at? ?? ?? ?? ?? ?? ?? ? : 07/10/2008 12:38:59
SQL Tuning Set (STS) Name? ?? ?? ?: test_sql_tuning_set
SQL Tuning Set Owner? ?? ?? ?? ???: TEST
DBMS_SQLTUNE.REPORT_TUNING_TASK('TEST_TUNING_TASK')
-------------------------------------------------------------------------------------------------------------------------------
Number of Statements in the STS? ?: 17
Number of Statements in the Report: 17
Number of Statements with Findings: 7
Number of Statistic Findings? ?? ?: 9
Number of SQL Profile Findings? ? : 2
Number of SQL Restructure Findings: 1
Number of Errors? ?? ?? ?? ?? ?? ?: 1
.........................................
.........................................
這里就不顯示分析結(jié)果了，上千行的分析結(jié)果。
和創(chuàng)建Tuning task類(lèi)似，select_sqlset也可以從AWR中獲得sql集合，也可拷貝其他集合。這里不再詳細(xì)介紹。
--d、通過(guò)manually specified statement設(shè)置Tuning任務(wù).
--沒(méi)有綁定變量的情況：
SQL> DECLARE
2? ? l_sql? ?? ?? ?? ?? ?VARCHAR2(500);
3? ? l_sql_tune_task_id??VARCHAR2(100);
4??BEGIN
5? ? l_sql := 'select /*We will trace this sql*/ name,addr,insertdata from
(select name,addr,insertdata,rank() over(partition by name,addr order by
insertdatadesc) rn from t ) where rn = 1';
7? ? l_sql_tune_task_id := DBMS_SQLTUNE.create_tuning_task (
8? ?? ?? ?? ?? ?? ?? ?? ?? ? sql_text? ? => l_sql,
9? ?? ?? ?? ?? ?? ?? ?? ?? ? user_name? ?=> 'TEST',
10? ?? ?? ?? ?? ?? ?? ?? ?? ? scope? ?? ? => DBMS_SQLTUNE.scope_comprehensive,
11? ?? ?? ?? ?? ?? ?? ?? ?? ? time_limit??=> 60,
12? ?? ?? ?? ?? ?? ?? ?? ?? ? task_name? ?=> 'test_tuning_task',
13? ?? ?? ?? ?? ?? ?? ?? ?? ? description => 'Tuning task for an a simple query.');
14? ? DBMS_OUTPUT.put_line('l_sql_tune_task_id: ' || l_sql_tune_task_id);
15??END;
16??/
PL/SQL 過(guò)程已成功完成。
SQL> EXEC DBMS_SQLTUNE.execute_tuning_task(task_name => 'test_tuning_task');
PL/SQL 過(guò)程已成功完成。
SQL> SELECT DBMS_SQLTUNE.report_tuning_task('test_tuning_task') AS recommendations FROM dual;
RECOMMENDATIONS
--------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name? ?? ?? ?? ?? ?? ?: test_tuning_task
Tuning Task Owner? ?? ?? ?? ?? ???: TEST
Scope? ?? ?? ?? ?? ?? ?? ?? ?? ???: COMPREHENSIVE
Time Limit(seconds)? ?? ?? ?? ?? ?: 60
Completion Status? ?? ?? ?? ?? ???: COMPLETED
Started at? ?? ?? ?? ?? ?? ?? ?? ?: 07/10/2008 01:17:09
Completed at? ?? ?? ?? ?? ?? ?? ? : 07/10/2008 01:17:09
Number of Statistic Findings? ?? ?: 1
RECOMMENDATIONS
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Schema Name: TEST
SQL ID? ???: 3zdbsrhb1mhuq? ?--該處的sql_id顯示不正確，可能是oracle的一個(gè) bug
SQL Text? ?: select /*We will trace this sql*/ name,addr,insertdata from
(select name,addr,insertdata,rank() over(partition by name,addr
order by insertdata desc) rn from t ) where rn = 1
-------------------------------------------------------------------------------
FINDINGS SECTION (1 finding)
-------------------------------------------------------------------------------
RECOMMENDATIONS
--------------------------------------------------------------------------------
1- Statistics Finding
---------------------
尚未分析表 "TEST"."
Recommendation
--------------
- 考慮收集此表的優(yōu)
execute dbms_stats.gather_table_stats(ownname => 'TEST', tabname => 'T',
estimate_percent => DBMS_STATS.AUTO_SAMPLE_SIZE, method_opt =>
'FOR ALL COLUMNS SIZE AUTO');
RECOMMENDATIONS
--------------------------------------------------------------------------------
Rationale
---------
為了選擇好的執(zhí)行計(jì)劃, 優(yōu)化程序需
-------------------------------------------------------------------------------
ADDITIONAL INFORMATION SECTION
-------------------------------------------------------------------------------
-優(yōu)化程序不能合并位于執(zhí)行計(jì)劃的行 ID 1 處的視圖。.
-------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
RECOMMENDATIONS
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
1- Original
-----------
Plan hash value: 3047187157
--------------------------------------------------------------------------------
| Id??| Operation? ?? ?? ?? ?? ? | Name | Rows??| Bytes | Cost (%CPU)| Time
--------------------------------------------------------------------------------
|? ?0 | SELECT STATEMENT? ?? ?? ?|? ?? ?|? ???8 |? ?368 |? ???4??(25)| 00:00:01
|*??1 |??VIEW? ?? ?? ?? ?? ?? ???|? ?? ?|? ???8 |? ?368 |? ???4??(25)| 00:00:01
RECOMMENDATIONS
--------------------------------------------------------------------------------
|*??2 |? ?WINDOW SORT PUSHED RANK|? ?? ?|? ???8 |? ?264 |? ???4??(25)| 00:00:01
|? ?3 |? ? TABLE ACCESS FULL? ???| T? ? |? ???8 |? ?264 |? ???3? ?(0)| 00:00:01
--------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("RN"=1)
2 - filter(RANK() OVER ( PARTITION BY "NAME","ADDR" ORDER BY
INTERNAL_FUNCTION("INSERTDATA") DESC )<=1)
RECOMMENDATIONS
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
--帶有綁定變量的情況：
SQL> variable var_1 number;
SQL> variable var_2 number;
SQL> variable var_3 number;
SQL> exec :var_1 := 5;
PL/SQL 過(guò)程已成功完成。
SQL> exec :var_2 := 4;
PL/SQL 過(guò)程已成功完成。
SQL> exec :var_3 := 3;
PL/SQL 過(guò)程已成功完成。
SQL> select id,name,addr from t where id<>:var_1 and id<:var_2 and id>
ID NAME? ?? ?? ?? ?? ???ADDR
---------- -------------------- --------------------
1 張? ?? ?? ?? ?? ?? ? 北京
2 張? ?? ?? ?? ?? ?? ? 北京
SQL> SELECT task_name, status FROM dba_advisor_log WHERE owner = 'TEST';
TASK_NAME? ?? ?? ?? ?? ?? ?? ? STATUS
------------------------------ -----------
ADDM:1184202927_1_201? ?? ?? ? COMPLETED
ADDM:1184202927_1_202? ?? ?? ? COMPLETED
test_tuning_task? ?? ?? ?? ?? ?COMPLETED
SQL> BEGIN
2? ???DBMS_SQLTUNE.drop_tuning_task (task_name => 'test_tuning_task');
3??END;
4??/
PL/SQL 過(guò)程已成功完成。
SQL>
SQL>
SQL> DECLARE
2? ? l_sql? ?? ?? ?? ?? ?VARCHAR2(500);
3? ? l_sql_tune_task_id??VARCHAR2(100);
4??BEGIN
5? ? l_sql := 'select id,name,addr from t where id<>:var_1 and id<:var_2 and i>
d<:var_3>
6
7? ? l_sql_tune_task_id := DBMS_SQLTUNE.create_tuning_task (
8? ?? ?? ?? ?? ?? ?? ?? ?? ? sql_text? ? => l_sql,
9? ?? ?? ?? ?? ?? ?? ?? ?? ? bind_list? ?=> sql_binds(anydata.ConvertNumber(5),
anydata.ConvertNumber(4),anydata.ConvertNumber(3)),
10? ?? ?? ?? ?? ?? ?? ?? ?? ? user_name? ?=> 'TEST',
11? ?? ?? ?? ?? ?? ?? ?? ?? ? scope? ?? ? => DBMS_SQLTUNE.scope_comprehensive,
12? ?? ?? ?? ?? ?? ?? ?? ?? ? time_limit??=> 60,
13? ?? ?? ?? ?? ?? ?? ?? ?? ? task_name? ?=> 'test_tuning_task',
14? ?? ?? ?? ?? ?? ?? ?? ?? ? description => 'Tuning task for an a simple query
.');
15? ? DBMS_OUTPUT.put_line('l_sql_tune_task_id: ' || l_sql_tune_task_id);
16??END;
17??/
PL/SQL 過(guò)程已成功完成。
SQL> SELECT * FROM DBA_SQLTUNE_BINDS;
TASK_ID??OBJECT_ID? ?POSITION VALUE()
---------- ---------- ---------- --------------------
393? ?? ?? ? 1? ?? ?? ? 1 ANYDATA()
393? ?? ?? ? 1? ?? ?? ? 2 ANYDATA()
393? ?? ?? ? 1? ?? ?? ? 3 ANYDATA()
SQL> EXEC DBMS_SQLTUNE.execute_tuning_task(task_name => 'test_tuning_task');
PL/SQL 過(guò)程已成功完成。
SQL> SELECT DBMS_SQLTUNE.report_tuning_task('test_tuning_task') AS recommendatio
ns FROM dual;
RECOMMENDATIONS
--------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name? ?? ?? ?? ?? ?? ?: test_tuning_task
Tuning Task Owner? ?? ?? ?? ?? ???: TEST
Scope? ?? ?? ?? ?? ?? ?? ?? ?? ???: COMPREHENSIVE
Time Limit(seconds)? ?? ?? ?? ?? ?: 60
Completion Status? ?? ?? ?? ?? ???: COMPLETED
Started at? ?? ?? ?? ?? ?? ?? ?? ?: 07/10/2008 02:04:29
Completed at? ?? ?? ?? ?? ?? ?? ? : 07/10/2008 02:04:29
Number of Statistic Findings? ?? ?: 1
RECOMMENDATIONS
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Schema Name: TEST
SQL ID? ???: 15c91q9b2sxvk? ?--該處的sql_id顯示不正確，可能是oracle的一個(gè) bug
SQL Text? ?: select id,name,addr from t where id<>:var_1 and id<:var_2 and>
id<:var_3>
-------------------------------------------------------------------------------
FINDINGS SECTION (1 finding)
-------------------------------------------------------------------------------
1- Statistics Finding
RECOMMENDATIONS
--------------------------------------------------------------------------------
---------------------
尚未分析表 "TEST"."
Recommendation
--------------
- 考慮收集此表的優(yōu)
execute dbms_stats.gather_table_stats(ownname => 'TEST', tabname => 'T',
estimate_percent => DBMS_STATS.AUTO_SAMPLE_SIZE, method_opt =>
'FOR ALL COLUMNS SIZE AUTO');
Rationale
RECOMMENDATIONS
--------------------------------------------------------------------------------
---------
為了選擇好的執(zhí)行計(jì)劃, 優(yōu)化程序需
-------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
-------------------------------------------------------------------------------
1- Original
-----------
Plan hash value: 1601196873
RECOMMENDATIONS
--------------------------------------------------------------------------------
--------------------------------------------------------------------------
| Id??| Operation? ?? ?? ?| Name | Rows??| Bytes | Cost (%CPU)| Time? ???|
--------------------------------------------------------------------------
|? ?0 | SELECT STATEMENT??|? ?? ?|? ???8 |? ?296 |? ???3? ?(0)| 00:00:01 |
|*??1 |??TABLE ACCESS FULL| T? ? |? ???8 |? ?296 |? ???3? ?(0)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("ID"<>:VAR_1 AND "ID"<:var_2 and>
RECOMMENDATIONS
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
三、SQL Profile：
由于缺少各種信息，優(yōu)化器有時(shí)候會(huì)產(chǎn)生不正確的執(zhí)行計(jì)劃，通常我們可以指定hints來(lái)干預(yù)執(zhí)行計(jì)劃。
SQL AUTO TUNING通過(guò)SQL Profiling來(lái)解決類(lèi)似的問(wèn)題。自動(dòng)調(diào)整優(yōu)化器會(huì)創(chuàng)建SQL Profile，SQL Profile包含SQL語(yǔ)句的輔助統(tǒng)計(jì)信息。
普通優(yōu)化模式下，優(yōu)化器通過(guò)估算出一個(gè)集式、選擇性、cost來(lái)最后決定使用什么樣的執(zhí)行計(jì)劃。SQL Profile利用存儲(chǔ)的額外的信息，
通過(guò)采樣或者部分執(zhí)行的方式來(lái)驗(yàn)證一個(gè)執(zhí)行計(jì)劃是否為最優(yōu)化，保存歷史運(yùn)行統(tǒng)計(jì)信息。
如果一個(gè)tuning task accept SQL Profile，SQL Profile將被永久存儲(chǔ)在數(shù)據(jù)字典中。普通優(yōu)化模式下，優(yōu)化器在產(chǎn)生執(zhí)行計(jì)劃的時(shí)候
將利用數(shù)據(jù)庫(kù)的統(tǒng)計(jì)信息結(jié)合SQL Profile的信息一起分析，最終產(chǎn)生最優(yōu)化的執(zhí)行計(jì)劃。
可以利用CATAGORY控制SQL Profile的使用權(quán)限，數(shù)據(jù)庫(kù)參數(shù)sqltune_category為默認(rèn)DEFAULT。
SQL> SHOW PARAMETER SQLTUNE
NAME? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?TYPE? ?? ???VALUE
------------------------------------ ----------- ------------------------------
sqltune_category? ?? ?? ?? ?? ?? ?? ?string? ?? ?DEFAULT
我們也可以修改數(shù)據(jù)庫(kù)參數(shù)文件，指定我們自己的SQLTUNE_CATEGORY：
ALTER SYSTEM SET SQLTUNE_CATEGORY = PROD;
SQL Profiles apply to the following statement types:
SELECT statements
UPDATE statements
INSERT statements (only with a SELECT clause)
DELETE statements
CREATE TABLE statements (only with the AS SELECT clause)
MERGE statements (the update or insert operations)
SQL Profile基本操作：
SQL> conn /as sysdba
已連接。
SQL> GRANT CREATE ANY SQL_PROFILE TO TEST;
授權(quán)成功。
SQL> GRANT DROP ANY SQL PROFILE TO TEST;
授權(quán)成功。
SQL> GRANT ALTER ANY SQL PROFILE TO TEST;
授權(quán)成功。
SQL> CONN TEST/TEST
已連接。
SET SERVEROUTPUT ON
DECLARE
l_sql_tune_task_id??VARCHAR2(20);
BEGIN
l_sql_tune_task_id := DBMS_SQLTUNE.accept_sql_profile (
task_name => 'test_tuning_task',
name? ?? ?=> 'test_profile');
DBMS_OUTPUT.put_line('l_sql_tune_task_id: ' || l_sql_tune_task_id);
END;
/
BEGIN
DBMS_SQLTUNE.alter_sql_profile (
name? ?? ?? ?? ?=> 'test_profile',
attribute_name??=> 'STATUS',
value? ?? ?? ???=> 'DISABLED');
END;
/
BEGIN
DBMS_SQLTUNE.drop_sql_profile (
name? ?=> 'test_profile',
ignore => TRUE);
END;
/
--example:
SQL> execute dbms_sqltune.accept_sql_profile(task_name => 'test_tuning_task',object_id => 6, replace => TRUE);
SQL> select count(1) from DBA_SQL_PROFILES;
COUNT(1)
----------
1
PL/SQL 過(guò)程已成功完成。
四、幾個(gè)有用的automatic SQL tuning相關(guān)的數(shù)據(jù)字典:
DBA_ADVISOR_TASKS
DBA_ADVISOR_FINDINGS
DBA_ADVISOR_RECOMMENDATIONS
DBA_ADVISOR_RATIONALE
DBA_SQLTUNE_STATISTICS
DBA_SQLTUNE_BINDS
DBA_SQLTUNE_PLANS
DBA_SQLSET
DBA_SQLSET_BINDS
DBA_SQLSET_STATEMENTS
DBA_SQLSET_REFERENCES
DBA_SQL_PROFILES
V$SQL
V$SQLAREA
V$ACTIVE_SESSION_HISTORY
五、DBMS_SQLTUNE包的詳細(xì)方法可以參考：
http://download-west.oracle.com/ ... b10802/d_sqltun.htm
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