固定执行计划-SQL PROFILE手工绑定

 

固定（稳定）执行计划

你的应用的功能时快时慢，变化比较大，功能的性能能够保持一种稳定的状态，ORACLE 固定执行计划，采用以下这几种方式

• oracle 9i使用 Outline
• oracle 10g采用 sql profile
• oracle 11g增加了sql plan manage

---

oracle 10g采用 sql profile ：两种模式

• 从SQL语句历史的执行计划，找到一个合理的，进行绑定
• 还有一种无法从历史的执行计划找到合理的，只能手工构造进行绑定

提供脚本

create_sql_profile

提供绑定shared pool中已有的执行计划中，找一个绑定或自己构造一个绑定

----------------------------------------------------------------------------------------
--
-- File name:   create_sql_profile.sql
--
-- Purpose:     Create SQL Profile based on Outline hints in V$SQL.OTHER_XML.
--
-- Author:      Kerry Osborne
--
-- Usage:       This scripts prompts for four values.
--
--              sql_id: the sql_id of the statement to attach the profile to (must be in the shared pool),if sql_id is not shared pool,must be bulid sql plan
--
--              child_no: the child_no of the statement from v$sql
--
--              new_sql_id:需要绑定的SQL语句
--
--              profile_name: the name of the profile to be generated
--
--              category: the name of the category for the profile
--
--              force_macthing: a toggle to turn on or off the force_matching feature
--
-- Description:
--
--              Based on a script by Randolf Giest.
--
-- Mods:        This is the 2nd version of this script which removes dependency on rg_sqlprof1.sql.
--
--              See kerryosborne.oracle-guy.com for additional information.
---------------------------------------------------------------------------------------
--

-- @rg_sqlprof1 '&&sql_id' &&child_no '&&new_sql_id' '&&category' '&force_matching'

set feedback off
set sqlblanklines on

accept sql_id -
       prompt 'Enter value for sql_id: ' -
       default 'X0X0X0X0'
accept child_no -
       prompt 'Enter value for child_no (0): ' -
       default '0'
accept new_sql_id -
       prompt 'Enter value for new_sql_id: ' -
       default '0'
accept profile_name -
       prompt 'Enter value for profile_name (PROF_sqlid_planhash): ' -
       default 'X0X0X0X0'
accept category -
       prompt 'Enter value for category (DEFAULT): ' -
       default 'DEFAULT'
accept force_matching -
       prompt 'Enter value for force_matching (TRUE): ' -
       default 'TRUE'

declare
ar_profile_hints sys.sqlprof_attr;
cl_sql_text clob;
l_profile_name varchar2(30);
begin
select
extractvalue(value(d), '/hint') as outline_hints
bulk collect
into
ar_profile_hints
from
xmltable('/*/outline_data/hint'
passing (
select
xmltype(other_xml) as xmlval
from
v$sql_plan
where
sql_id = '&&sql_id'
and child_number = &&child_no
and other_xml is not null
)
) d;

select
sql_fulltext,
decode('&&profile_name','X0X0X0X0','PROF_&&sql_id'||'_'||plan_hash_value,'&&profile_name')
into
cl_sql_text, l_profile_name
from
v$sqlarea
where
sql_id = '&&new_sql_id';

dbms_sqltune.import_sql_profile(
sql_text => cl_sql_text,
profile => ar_profile_hints,
category => '&&category',
name => l_profile_name,
force_match => &&force_matching
-- replace => true
);

  dbms_output.put_line(' ');
  dbms_output.put_line('SQL Profile '||l_profile_name||' created.');
  dbms_output.put_line(' ');

exception
when NO_DATA_FOUND then
  dbms_output.put_line(' ');
  dbms_output.put_line('ERROR: sql_id: '||'&&sql_id'||' Child: '||'&&child_no'||' not found in v$sql.');
  dbms_output.put_line('ERROR: sql_id: '||'&&new_sql_id'||' not found in v$sqlarea.');
  dbms_output.put_line(' ');

end;
/

undef sql_id
undef new_sql_id
undef child_no
undef profile_name
undef category
undef force_matching

set sqlblanklines off
set feedback on

create_sql_profile