24.Oracle深度学习笔记——使用存储提纲
2016-03-08 21:55
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24.Oracle深度学习笔记——使用存储提纲
欢迎转载，转载请标明出处：http://blog.csdn.net/notbaron/article/details/50830916
oracle存储提纲（stored outline）用来提供稳定的执行计划，以消除执行环境或者对象统计信息的改变造成的影响。因此，这个特性也被称作计划稳定性。具体的讲，存储提纲是一个提示的集合，更精确地说，所有这些提示强制查询优化器为一个给定的SQL语句，稳定地产生一个特殊的执行计划。但实践中，即使使用存储提纲，还是可能观察到执行计划的改变。不是总能提供一个稳定的执行计划，Oracle 11g版本起，不再赞成使用存储提纲，而是推荐SQL计划基线。
在CBO之后不久被引入，最早基于提示的机制。
9i对大纲进行了增强，10gR1后就没有对该特性做过任何事情了。在11g官方文档中称该特性已经被弃用不再维护了。
我们先来看看如何使用的如下：
tpcc@TOADDB> create table oln_test as select *from dba_tables;
Table created.
tpcc@TOADDB> create index idex_oln on oln_test (TABLE_NAME);
Index created.
tpcc@TOADDB> set autotrace on;
tpcc@TOADDB> select OWNER from oln_test wheretable_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 2108416138
------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
------------------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 2 (0)| 00:00:01 |
| 1| TABLE ACCESS BY INDEX ROWID BATCHED|OLN_TEST | 1 | 26 | 2 (0)| 00:00:01 |
|* 2| INDEX RANGE SCAN | IDEX_OLN | 1 | | 1 (0)| 00:00:01 |
------------------------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
2- access("TABLE_NAME"='OLN_TEST')
Statistics
----------------------------------------------------------
98 recursive calls
0 dbblock gets
73 consistent gets
6 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
6 sorts (memory)
0 sorts (disk)
0 rowsprocessed
然后加入HINT如下：
tpcc@TOADDB> select /*+FULL(oln_test)*/ OWNER fromoln_test where table_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 1307524366
------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 30 (0)| 00:00:01 |
|* 1| TABLE ACCESS FULL| OLN_TEST | 1 | 26| 30 (0)| 00:00:01 |
------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1- filter("TABLE_NAME"='OLN_TEST')
Statistics
----------------------------------------------------------
1 recursivecalls
0 dbblock gets
98 consistent gets
95 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rowsprocessed
tpcc@TOADDB> set autotrace off;
tpcc@TOADDB> CREATE OR REPLACE OUTLINE oln_to ONselect OWNER from oln_test where table_name = 'OLN_TEST';
Outline created.
tpcc@TOADDB> CREATE OR REPLACE OUTLINE oln_hint ONselect /*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST';
Outline created.
查看DBA_OUTLINES如下：
sys@TOADDB> desc dba_outlines;
Name Null? Type
------------------------------------------------------------- ------------------------------------
NAME VARCHAR2(128)
OWNER VARCHAR2(128)
CATEGORY VARCHAR2(128)
USED VARCHAR2(6)
TIMESTAMP DATE
VERSION VARCHAR2(64)
SQL_TEXT LONG
SIGNATURE RAW(16)
COMPATIBLE VARCHAR2(12)
ENABLED VARCHAR2(8)
FORMAT VARCHAR2(6)
MIGRATED VARCHAR2(12)
sys@TOADDB> select count(*) from dba_outlines;
COUNT(*)
----------
2
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-----------------------------------------------------------------------------------------------
OLN_TO selectOWNER from oln_test where table_name = 'OLN_TEST'
OLN_HINT select/*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST'
当前共两行，就是我们之前创建的两项。
交换可以使用如下命令进行：
sys@TOADDB> UPDATE DBA_OUTLINES SETNAME=DECODE(NAME,'OLN_HINT','OLN_TO','OLN_TO','OLN_HINT') WHERE NAME IN('OLN_TO','OLN_HINT');
2 rows updated.
sys@TOADDB> commit;
Commit complete.
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-----------------------------------------------------------------------------------------------
OLN_HINT selectOWNER from oln_test where table_name = 'OLN_TEST'
OLN_TO select/*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST'
检验如下：
tpcc@TOADDB> alter system flush shared_pool;
tpcc@TOADDB> set autotrace on;
12C需要设置：sys@TOADDB>alter system set use_stored_outlines=true;
tpcc@TOADDB> select OWNER from oln_test wheretable_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 1307524366
------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 30 (0)| 00:00:01 |
|* 1| TABLE ACCESS FULL| OLN_TEST | 1 | 26| 30 (0)| 00:00:01 |
-----------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1- filter("TABLE_NAME"='OLN_TEST')
Note
-----
-outline "OLN_HINT" used for this statement
Statistics
----------------------------------------------------------
0 recursive calls
0 dbblock gets
98 consistent gets
0 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rows processed
删除OUTLINE：
tpcc@TOADDB> drop outline oln_to;
Outline dropped.
tpcc@TOADDB> drop outline oln_hint;
Outline dropped.
tpcc@TOADDB> select count(*) from oln_test;
COUNT(*)
----------
2476
tpcc@TOADDB> col sql_id format a20;
tpcc@TOADDB> col sql_text format a40;
tpcc@TOADDB> select sql_id,hash_value,child_number, sql_text from v$sql where sql_text like 'select count(*) fromoln_test%';
SQL_ID HASH_VALUE CHILD_NUMBER SQL_TEXT
-------------------- ---------------------- ----------------------------------------
24z60pxhd61h9 1624442377 0 select count(*) from oln_test
使能会话创建存储提纲
tpcc@TOADDB> alter session setcreate_stored_outlines = true;
Session altered.
通过SQL的HASH值来创建存储提纲如下：
tpcc@TOADDB> execdbms_outln.create_outline(hash_value => 1624442377,child_number =>0);
PL/SQL procedure successfully completed.
执行检查测试如下：
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-------------------------------------------------------
SYS_OUTLINE_160 select count(*) from oln_test
30517132219819
SYS_OUTLINE_160 select sql_id,hash_value,child_number,
30517132615720 sql_text from v$sql where sql_text like
'selectcount(*) from oln_test%'
SYS_OUTLINE_160 select count(*) fromdba_outlines
30517140764322
SYS_OUTLINE_160 select name,sql_text fromdba_outlines
30517143173123
tpcc@TOADDB>set autotrace on;
tpcc@TOADDB> select count(*) from oln_test;
COUNT(*)
----------
2476
Execution Plan
----------------------------------------------------------
Plan hash value: 2860217201
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1| 5 (0)| 00:00:01 |
| 1| SORT AGGREGATE | | 1| | |
| 2| INDEX FAST FULL SCAN| IDEX_OLN | 2476 | 5 (0)| 00:00:01 |
--------------------------------------------------------------------------
Note
-----
- outline"SYS_OUTLINE_16030516461948302" used for this statement
Statistics
----------------------------------------------------------
0 recursive calls
0 dbblock gets
17 consistent gets
0 physical reads
0 redosize
543 bytes sent via SQL*Net to client
551 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rowsprocessed
alter system set use_stored_outlines=false;
disable/enable具体outline：
alter outline ol_name disable;
alter outline ol_name enable;
删除：outlinecategory：
outline相关视图：
dba_outlines
dba_outline_hints 该视图列出outline的hints内容
检查outline是否存在：
select name, category, owner from dba_outlines;
可以用如下命令分别删除指定的outline或者某个类别下的所有outline：
drop outline dh_test1;
dbms_outln.drop_by_cat(cat=>'Default');
欢迎转载，转载请标明出处：http://blog.csdn.net/notbaron/article/details/50830916
oracle存储提纲（stored outline）用来提供稳定的执行计划，以消除执行环境或者对象统计信息的改变造成的影响。因此，这个特性也被称作计划稳定性。具体的讲，存储提纲是一个提示的集合，更精确地说，所有这些提示强制查询优化器为一个给定的SQL语句，稳定地产生一个特殊的执行计划。但实践中，即使使用存储提纲，还是可能观察到执行计划的改变。不是总能提供一个稳定的执行计划，Oracle 11g版本起，不再赞成使用存储提纲，而是推荐SQL计划基线。
在CBO之后不久被引入，最早基于提示的机制。
9i对大纲进行了增强，10gR1后就没有对该特性做过任何事情了。在11g官方文档中称该特性已经被弃用不再维护了。
我们先来看看如何使用的如下：
1. 测试一
在12.1.0.2.0版本上进行的测试tpcc@TOADDB> create table oln_test as select *from dba_tables;
Table created.
tpcc@TOADDB> create index idex_oln on oln_test (TABLE_NAME);
Index created.
tpcc@TOADDB> set autotrace on;
tpcc@TOADDB> select OWNER from oln_test wheretable_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 2108416138
------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
------------------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 2 (0)| 00:00:01 |
| 1| TABLE ACCESS BY INDEX ROWID BATCHED|OLN_TEST | 1 | 26 | 2 (0)| 00:00:01 |
|* 2| INDEX RANGE SCAN | IDEX_OLN | 1 | | 1 (0)| 00:00:01 |
------------------------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
2- access("TABLE_NAME"='OLN_TEST')
Statistics
----------------------------------------------------------
98 recursive calls
0 dbblock gets
73 consistent gets
6 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
6 sorts (memory)
0 sorts (disk)
0 rowsprocessed
然后加入HINT如下：
tpcc@TOADDB> select /*+FULL(oln_test)*/ OWNER fromoln_test where table_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 1307524366
------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 30 (0)| 00:00:01 |
|* 1| TABLE ACCESS FULL| OLN_TEST | 1 | 26| 30 (0)| 00:00:01 |
------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1- filter("TABLE_NAME"='OLN_TEST')
Statistics
----------------------------------------------------------
1 recursivecalls
0 dbblock gets
98 consistent gets
95 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rowsprocessed
1.1 创建OUTLINE
生成存储提纲如下：tpcc@TOADDB> set autotrace off;
tpcc@TOADDB> CREATE OR REPLACE OUTLINE oln_to ONselect OWNER from oln_test where table_name = 'OLN_TEST';
Outline created.
tpcc@TOADDB> CREATE OR REPLACE OUTLINE oln_hint ONselect /*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST';
Outline created.
1.2 交换OUTLINE
直接更新DBA_OUTLINES表查看DBA_OUTLINES如下：
sys@TOADDB> desc dba_outlines;
Name Null? Type
------------------------------------------------------------- ------------------------------------
NAME VARCHAR2(128)
OWNER VARCHAR2(128)
CATEGORY VARCHAR2(128)
USED VARCHAR2(6)
TIMESTAMP DATE
VERSION VARCHAR2(64)
SQL_TEXT LONG
SIGNATURE RAW(16)
COMPATIBLE VARCHAR2(12)
ENABLED VARCHAR2(8)
FORMAT VARCHAR2(6)
MIGRATED VARCHAR2(12)
sys@TOADDB> select count(*) from dba_outlines;
COUNT(*)
----------
2
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-----------------------------------------------------------------------------------------------
OLN_TO selectOWNER from oln_test where table_name = 'OLN_TEST'
OLN_HINT select/*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST'
当前共两行，就是我们之前创建的两项。
交换可以使用如下命令进行：
sys@TOADDB> UPDATE DBA_OUTLINES SETNAME=DECODE(NAME,'OLN_HINT','OLN_TO','OLN_TO','OLN_HINT') WHERE NAME IN('OLN_TO','OLN_HINT');
2 rows updated.
sys@TOADDB> commit;
Commit complete.
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-----------------------------------------------------------------------------------------------
OLN_HINT selectOWNER from oln_test where table_name = 'OLN_TEST'
OLN_TO select/*+FULL(oln_test)*/ OWNER from oln_test where table_name = 'OLN_TEST'
检验如下：
tpcc@TOADDB> alter system flush shared_pool;
tpcc@TOADDB> set autotrace on;
12C需要设置：sys@TOADDB>alter system set use_stored_outlines=true;
tpcc@TOADDB> select OWNER from oln_test wheretable_name = 'OLN_TEST';
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 1307524366
------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1 | 26 | 30 (0)| 00:00:01 |
|* 1| TABLE ACCESS FULL| OLN_TEST | 1 | 26| 30 (0)| 00:00:01 |
-----------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1- filter("TABLE_NAME"='OLN_TEST')
Note
-----
-outline "OLN_HINT" used for this statement
Statistics
----------------------------------------------------------
0 recursive calls
0 dbblock gets
98 consistent gets
0 physical reads
0 redosize
341 bytes sent via SQL*Net to client
540 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rows processed
删除OUTLINE：
tpcc@TOADDB> drop outline oln_to;
Outline dropped.
tpcc@TOADDB> drop outline oln_hint;
Outline dropped.
1.3 通过SHARED POOL中SQL创建OUTLINE
需要10G 以上，蛤蟆在12C上进行的操作tpcc@TOADDB> select count(*) from oln_test;
COUNT(*)
----------
2476
tpcc@TOADDB> col sql_id format a20;
tpcc@TOADDB> col sql_text format a40;
tpcc@TOADDB> select sql_id,hash_value,child_number, sql_text from v$sql where sql_text like 'select count(*) fromoln_test%';
SQL_ID HASH_VALUE CHILD_NUMBER SQL_TEXT
-------------------- ---------------------- ----------------------------------------
24z60pxhd61h9 1624442377 0 select count(*) from oln_test
使能会话创建存储提纲
tpcc@TOADDB> alter session setcreate_stored_outlines = true;
Session altered.
通过SQL的HASH值来创建存储提纲如下：
tpcc@TOADDB> execdbms_outln.create_outline(hash_value => 1624442377,child_number =>0);
PL/SQL procedure successfully completed.
执行检查测试如下：
tpcc@TOADDB> select name,sql_text fromdba_outlines;
NAME SQL_TEXT
-------------------------------------------------------
SYS_OUTLINE_160 select count(*) from oln_test
30517132219819
SYS_OUTLINE_160 select sql_id,hash_value,child_number,
30517132615720 sql_text from v$sql where sql_text like
'selectcount(*) from oln_test%'
SYS_OUTLINE_160 select count(*) fromdba_outlines
30517140764322
SYS_OUTLINE_160 select name,sql_text fromdba_outlines
30517143173123
tpcc@TOADDB>set autotrace on;
tpcc@TOADDB> select count(*) from oln_test;
COUNT(*)
----------
2476
Execution Plan
----------------------------------------------------------
Plan hash value: 2860217201
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 1| 5 (0)| 00:00:01 |
| 1| SORT AGGREGATE | | 1| | |
| 2| INDEX FAST FULL SCAN| IDEX_OLN | 2476 | 5 (0)| 00:00:01 |
--------------------------------------------------------------------------
Note
-----
- outline"SYS_OUTLINE_16030516461948302" used for this statement
Statistics
----------------------------------------------------------
0 recursive calls
0 dbblock gets
17 consistent gets
0 physical reads
0 redosize
543 bytes sent via SQL*Net to client
551 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rowsprocessed
2. 存储提供维护命令
停止db使用outline功能：alter system set use_stored_outlines=false;
disable/enable具体outline：
alter outline ol_name disable;
alter outline ol_name enable;
删除：outlinecategory：
outline相关视图：
dba_outlines
dba_outline_hints 该视图列出outline的hints内容
检查outline是否存在：
select name, category, owner from dba_outlines;
可以用如下命令分别删除指定的outline或者某个类别下的所有outline：
drop outline dh_test1;
dbms_outln.drop_by_cat(cat=>'Default');
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