2015-05-28 Created By BaoXinjian
一、摘要
1. 应用场景
当运行很久的Job突然出现性能问题时，并排除数据量突然变大，可能原因有执行的脚本的某些对应的SQL的解析计划变更
2. 解决步骤
Step1. 通过对应的User或者其他信息查找Session ID
Step2. 通过Session_ID查看该SQL_ID历史的解析计划变换
Step3. 如果最近发生解析计划变更，并导致效率变慢，通过SPM绑定之前的解析计划
Step4. 确定解析计划是否绑定
Step5. 如果脚本还在运行，让客户停掉脚本，并重新运行，以测试绑定的新的解析计划是否满足期望
Step6. 如果绑定的解析计划并不能解决性能问题，验证后将其删除
二、步骤
Step1. 通过对应的User或者其他信息查找Session ID
select sql_id, username, osuser, machine, program from v$session where username = 'gavin'
Step2. 查看该SQL_ID历史的解析计划变换
select distinct a.instance_number, trunc(b.begin_interval_time, 'mi'), sql_id, plan_hash_value from dba_hist_sqlstat a, dba_hist_snapshot b where a.snap_id = b.snap_id and sql_id = '089dbukv1aanh' order by 2, 1
Step3. 如果最近发生解析计划变更，并导致效率变慢，通过SPM绑定之前的解析计划 (脚本coe_xfr_sql_baseline.sql)
SQL>@D:\Gavin\coe_xfr_sql_baseline.sqlParameter 1:SQL_ID (required)Enter value for 1: 089dbukv1aanhSNAP_DATE SQL_ID PLAN_HASH_VALUE--------------- ------------- --------------------2015/05/20 089dbukv1aanh 13887349532015/05/21 089dbukv1aanh 13887349532015/05/22 089dbukv1aanh 13887349532015/05/23 089dbukv1aanh 13887349532015/05/24 089dbukv1aanh 13887349532015/05/25 089dbukv1aanh 13887349532015/05/26 089dbukv1aanh 13887349532015/05/27 089dbukv1aanh 13887349532015/05/28 089dbukv1aanh 1388734953Parameter 2:PLAN_HASH_VALUE (required)Enter value for 2: 1388734953Values passed to coe_xfr_sql_baseline:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~SQL_ID: "089dbukv1aanh"PLAN_HASH_VALUE: "1388734953"SQL>SET ECHO OFF;SQL tuning set SS_089dbukv1aanh_1388734953 created.SQLSET_NAME SQLSET_OWNER SQL_ID PLAN_HASH_VALUE------------------------------ ------------------------------ ------------------------------ -------SS_089dbukv1aanh_1388734953 GAVIN 089dbukv1aanh 1388734953Plans Loaded: 1sys_sql_handle: "SYS_SQL_70445f05461a3cd3"sys_plan_name: "SQL_PLAN_70j2z0p31ng6m125daea2"1 plan(s) modified description: "SQL_ID: 089DBUKV1AANH PLAN HASH VALUE: 1388734953 CREATED BY COE_XFSQL tuning set SS_089dbukv1aanh_1388734953 dropped.SQL>REMSQL>REM SQL Plan BaselineSQL>REM ~~~~~~~~~~~~~~~~~SQL>REMSQL>SELECT signature, sql_handle, plan_name, enabled, accepted, fixed--, reproduced (avail on 11.2.0 2 FROM dba_sql_plan_baselines WHERE plan_name = :plan_name; SIGNATURE SQL_HANDLE PLAN_NAME ENA ACC FIX-------------------- ------------------------------ ------------------------------ --- --- --- 8089695306919853267 SYS_SQL_70445f05461a3cd3 SQL_PLAN_70j2z0p31ng6m125daea2 YES YES YESSQL>SQL>col description for a100SQL>SELECT description 2 FROM dba_sql_plan_baselines WHERE plan_name = :plan_name;DESCRIPTION----------------------------------------------------------------------------------------------------SQL_ID: 089DBUKV1AANH PLAN HASH VALUE: 1388734953 CREATED BY COE_XFR_SQL_BASELINE.SQLSQL>SET ECHO OFF;coe_xfr_sql_baseline completed.
Step4. 确定解析计划是否绑定
select sql_handle, plan_name, sql_text, creator, description, enabled, accepted, fixed from dba_sql_plan_baselines where description like '%089dbukv1aanh%'
Step5. 如果脚本还在运行，让客户停掉脚本，并重新运行，以测试绑定的新的解析计划是否满足期望
alter system disconnect session '102,102' immediate;
Step6. 如果绑定的解析计划并不能解决性能问题，验证后将其删除
declare l_plan number;begin l_plan := dbms_spm.drop_sql_plan_baseline('SYS_SQL_70445f05461a3cd3', 'SQL_PLAN_70j2z0p31ng6m125daea2'); dbms_output.put_line('l_pan=' || l_plan);end;
三、代码
Oracle Metalink下载代码 - ce_xfr_sql_baseline.sql
SPO coe_xfr_sql_baseline.log;SET DEF ON TERM OFF ECHO ON FEED OFF VER OFF HEA ON LIN 2000 PAGES 100 LONG 8000000 LONGC 800000 TRIMS ON TI OFF TIMI OFF SERVEROUT ON SIZE 1000000 NUM 20 SQLP SQL>;SET SERVEROUT ON SIZE UNL;REMREM Created according to coe_load_sql_baseline.sql and MOS note 789888.1 2013/06/10REMREM AUTHORREM gavin.baoREMREM SCRIPTREM coe_xfr_sql_baseline.sqlREMREM DESCRIPTIONREM This script loads a plan from AWR into the SQLREM Plan Baseline of the specified SQL.REMREM PRE-REQUISITESREM 1. Have in AWR the text for the specified SQL.REMREM PARAMETERSREM 1. SQL_ID (required)REM 2. PLAN_HASH_VALUE in AWR (required)REMREM EXECUTIONREM 1. Connect into SQL*Plus as user with access to data dictionaryREM and privileges to create SQL Plan Baselines. Do not use SYS.REM 2. Execute script coe_xfr_sql_baseline.sql passing first twoREM parameters inline or until requested by script.REMREM EXAMPLEREM # sqlplus systemREM SQL> START coe_xfr_sql_baseline.sql gnjy0mn4y9pbm b8f3mbkd8bkghREM SQL> START coe_xfr_sql_baseline.sql;REMREM NOTESREM 1. This script works on 11g or higher.REM 2. For a similar script for 10g use coe_xfr_sql_profile.sql,REM which uses custom SQL Profiles instead of SQL Baselines.REM 3. For possible errors see coe_xfr_sql_baseline.logREM 4. Use a DBA user but not SYS. Do not connect as SYS as the stagingREM table cannot be created in SYS schema and you will receive an error:REM ORA-19381: cannot create staging table in SYS schemaREMSET TERM ON ECHO OFF;PROPRO Parameter 1:PRO SQL_ID (required)PRODEF sql_id = '&1';PROcol SNAP_DATE for a15select distinct to_char(trunc(b.BEGIN_INTERVAL_TIME),'yyyy/mm/dd') SNAP_DATE,SQL_ID,PLAN_HASH_VALUEfrom dba_hist_sqlstat a,dba_hist_snapshot bwhere SQL_ID=TRIM('&&sql_id.')and a.snap_id=b.snap_id order by 1;PROPRO Parameter 2:PRO PLAN_HASH_VALUE (required)PRODEF plan_hash_value = '&2';PROPRO Values passed to coe_xfr_sql_baseline:PRO ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~PRO SQL_ID: "&&sql_id."PRO PLAN_HASH_VALUE: "&&plan_hash_value."PROWHENEVER SQLERROR EXIT SQL.SQLCODE;SET TERM OFF ECHO ON;-- trim parametersCOL sql_id NEW_V sql_id FOR A30;COL plan_hash_value NEW_V plan_hash_value FOR A30;SELECT TRIM('&&sql_id.') sql_id, TRIM('&&plan_hash_value.') plan_hash_value FROM DUAL;-- open log fileSPO coe_xfr_sql_baseline_&&sql_id..log;GET coe_xfr_sql_baseline.log;.-- get userCOL connected_user NEW_V connected_user FOR A30;SELECT USER connected_user FROM DUAL;VAR sql_text CLOB;VAR plan_name VARCHAR2(30);VAR b_snap_id NUMBER;VAR e_snap_id NUMBER;VAR ss_name VARCHAR2(100);EXEC :sql_text := NULL;EXEC :plan_name := NULL;EXEC :b_snap_id := NULL;EXEC :e_snap_id := NULL;EXEC :ss_name := 'SS_'||TRIM('&&sql_id.')||'_'||TRIM('&&plan_hash_value.');-- get sql_text from awrBEGIN SELECT REPLACE(sql_text, CHR(00), ' ') INTO :sql_text FROM dba_hist_sqltext WHERE sql_id = TRIM('&&sql_id.') AND sql_text IS NOT NULL AND ROWNUM = 1;EXCEPTION WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('getting sql_text from awr: '||SQLERRM); :sql_text := NULL;END;/-- sql_text as foundSELECT :sql_text FROM DUAL;-- check is sql_text for sql is availableSET TERM ON;SET ECHO OFF;BEGIN IF :sql_text IS NULL THEN RAISE_APPLICATION_ERROR(-20100, 'SQL_TEXT for SQL_ID &&sql_id. was not found in AWR (dba_hist_sqltext).'); END IF;END;/-- get snap idDECLARE l_count NUMBER;BEGIN SELECT min(SNAP_ID), max(SNAP_ID) INTO :b_snap_id, :e_snap_id FROM dba_hist_sqlstat WHERE sql_id = TRIM('&&sql_id.') AND plan_hash_value = TO_NUMBER(TRIM('&&plan_hash_value.')); IF (:b_snap_id is null or :e_snap_id is null) THEN RAISE_APPLICATION_ERROR(-20110, 'PHV &&plan_hash_value. for SQL_ID &&sql_id. was not be found in AWR (dba_hist_sqlstat).'); END IF;END;/DECLARE --ss_name VARCHAR2(100) default 'SS_'||TRIM('&&sql_id.')||'_'||TRIM('&&plan_hash_value.'); baseline_ref_cursor DBMS_SQLTUNE.SQLSET_CURSOR;BEGIN -- create sql_plan_baseline for sql using plan from AWR DBMS_SQLTUNE.CREATE_SQLSET(:ss_name); open baseline_ref_cursor for select VALUE(p) from table(DBMS_SQLTUNE.SELECT_WORKLOAD_REPOSITORY(:b_snap_id, :e_snap_id, 'sql_id='||CHR(39)||TRIM('&&sql_id.')||CHR(39)|| ' and plan_hash_value='||TRIM('&&plan_hash_value.'), NULL,NULL,NULL,NULL,NULL,NULL,'ALL')) p; DBMS_SQLTUNE.LOAD_SQLSET(:ss_name, baseline_ref_cursor); DBMS_OUTPUT.PUT_LINE('SQL tuning set '||:ss_name||' created.');END;/-- display details of the SQL tuning setcol PLAN_HASH_VALUE clearselect SQLSET_NAME,SQLSET_OWNER,SQL_ID,PLAN_HASH_VALUE from dba_sqlset_statements where sqlset_name = :ss_name ;-- load the plan from SQL tuning set into baselinedeclare plans NUMBER; description VARCHAR2(500); sys_sql_handle VARCHAR2(30); sys_plan_name VARCHAR2(30);begin plans := dbms_spm.load_plans_from_sqlset(sqlset_name => :ss_name, sqlset_owner => USER, fixed => 'YES', enabled => 'YES'); commit; DBMS_OUTPUT.PUT_LINE('Plans Loaded: '||plans); -- find handle and plan_name for sql_plan_baseline just created SELECT sql_handle, plan_name INTO sys_sql_handle, sys_plan_name FROM dba_sql_plan_baselines WHERE creator = USER AND origin = 'MANUAL-LOAD' AND created = ( -- past 1 minute only SELECT MAX(created) max_created FROM dba_sql_plan_baselines WHERE creator = USER AND origin = 'MANUAL-LOAD' AND created > SYSDATE - (1/24/60)); DBMS_OUTPUT.PUT_LINE('sys_sql_handle: "'||sys_sql_handle||'"'); DBMS_OUTPUT.PUT_LINE('sys_plan_name: "'||sys_plan_name||'"'); :plan_name := sys_plan_name; -- update description of new sql_plan_baseline description := UPPER('SQL_ID: '||TRIM('&&sql_id.')||' Plan Hash Value: '||TRIM('&&plan_hash_value.')||' created by coe_xfr_sql_baseline.sql'); plans := DBMS_SPM.ALTER_SQL_PLAN_BASELINE ( sql_handle => sys_sql_handle, plan_name => sys_plan_name, attribute_name => 'description', attribute_value => description ); DBMS_OUTPUT.PUT_LINE(plans||' plan(s) modified description: "'||description||'"'); DBMS_SQLTUNE.DROP_SQLSET(:ss_name); DBMS_OUTPUT.PUT_LINE('SQL tuning set '||:ss_name||' dropped.');end;/-- display details of new sql_plan_baselineSET ECHO ON;REMREM SQL Plan BaselineREM ~~~~~~~~~~~~~~~~~REMSELECT signature, sql_handle, plan_name, enabled, accepted, fixed--, reproduced (avail on 11.2.0.2) FROM dba_sql_plan_baselines WHERE plan_name = :plan_name;col description for a100SELECT description FROM dba_sql_plan_baselines WHERE plan_name = :plan_name;SET ECHO OFF;PROSPO OFF;WHENEVER SQLERROR CONTINUE;SET DEF ON TERM ON ECHO OFF FEED 6 VER ON HEA ON LIN 80 PAGES 14 LONG 80 LONGC 80 TRIMS OFF TI OFF TIMI OFF SERVEROUT OFF NUM 10 SQLP SQL>;SET SERVEROUT OFF;UNDEFINE 1 2 sql_id plan_hash_valueCL COLPROPRO coe_xfr_sql_baseline completed.
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