一 創建測試表create table a nologging as select * from all_objects;
二 準備工做
找到sql_Id='aq03p7muwgvq5'select * from V$sql where sql_text like '% from a where object_id=3%';
找到全表的outline:
方法一:dba_hist_sql_plan/v$sql_plan均可以sql
select extractvalue(value(d), '/hint') as outline_hints from xmltable('/*/outline_data/hint' passing ( select xmltype(other_xml) as xmlval from dba_hist_sql_plan where sql_id = '&sql_id' and plan_hash_value=&plan_hash_value and other_xml is not null)) d
方法二:session
select * from dbms_xplan.display_awr('aq03p7muwgvq5',0,'outline'); /*+ BEGIN_OUTLINE_DATA IGNORE_OPTIM_EMBEDDED_HINTS OPTIMIZER_FEATURES_ENABLE('11.2.0.4') DB_VERSION('11.2.0.4') ALL_ROWS OUTLINE_LEAF(@"SEL$1") FULL(@"SEL$1" "A"@"SEL$1") END_OUTLINE_DATA */
declare v_hints sys.sqlprof_attr; v_sqltext clob; begin select sql_fulltext into v_sqltext from v$sql where sql_id='aq03p7muwgvq5' and rownum<2; v_hints:=sys.sqlprof_attr(q'[FULL(@"SEL$1" "A"@"SEL$1")]'); dbms_sqltune.import_sql_profile(v_sqltext,v_hints,'sql_full',force_match=>true,replace=>true); end;
創建索引
create index I_ind_object_id_com on a(object_id,object_name) nologging;
查看執行計劃,並無走索引:oracle
Execution Plan ---------------------------------------------------------- Plan hash value: 2248738933 -------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | -------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 177 (1)| 00:00:01 | |* 1 | TABLE ACCESS FULL| A | 1 | 98 | 177 (1)| 00:00:01 | -------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("OBJECT_ID"=3) Note ----- - SQL profile "sql_full" used for this statement Statistics ---------------------------------------------------------- 7 recursive calls 0 db block gets 1254 consistent gets 1246 physical reads 0 redo size 1606 bytes sent via SQL*Net to client 519 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed
刪除profile app
begin dbms_sqltune.drop_sql_profile('sql_full'); end;
再次執行sql,找到走索引的outlineide
select * from dbms_xplan.display_awr('aq03p7muwgvq5',1,'outline'); /*+ BEGIN_OUTLINE_DATA IGNORE_OPTIM_EMBEDDED_HINTS OPTIMIZER_FEATURES_ENABLE('11.2.0.4') DB_VERSION('11.2.0.4') ALL_ROWS OUTLINE_LEAF(@"SEL$1") INDEX_RS_ASC(@"SEL$1" "A"@"SEL$1" ("A"."OBJECT_ID" "A"."OBJECT_NAME")) END_OUTLINE_DATA */
declare v_hints sys.sqlprof_attr; v_sqltext clob; begin select sql_fulltext into v_sqltext from v$sql where sql_id='aq03p7muwgvq5' and rownum<2; v_hints:=sys.sqlprof_attr( q'[INDEX_RS_ASC(@"SEL$1" "A"@"SEL$1" ("A"."OBJECT_ID" "A"."OBJECT_NAME"))]'); dbms_sqltune.import_sql_profile(v_sqltext,v_hints,'sql_comp_ind',force_match=>true,replace=>true); end;
創建更優的索引create index I_ind_object_id on a(object_Id) nologging;
再次查看執行計劃,並無走更優的索引測試
Execution Plan ---------------------------------------------------------- Plan hash value: 3075844428 --------------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | --------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 3 (0)| 00:00:01 | | 1 | TABLE ACCESS BY INDEX ROWID| A | 1 | 98 | 3 (0)| 00:00:01 | |* 2 | INDEX RANGE SCAN | I_IND_OBJECT_ID_COM | 1 | | 2 (0)| 00:00:01 | ------------------------------------------------------------------------ Predicate Information (identified by operation id): -------------------------------------------------- 2 - access("OBJECT_ID"=3) Note ----- - SQL profile "sql_comp_ind" used for this statement Statistics
7 recursive calls 0 db block gets 10 consistent gets 1 physical reads 0 redo size 1609 bytes sent via SQL*Net to client 519 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed
固然你也能夠用SQLT裏的coe_xfr_sql_profile.sql或者create_sql_profile.sql生成sql_profile;this
這裏有一點比較扯的是用完整的outline,寫進去不報錯,但執行計劃不走sql_profile里約定的內容;code
declare v_hints sys.sqlprof_attr; v_sqltext clob; begin select sql_fulltext into v_sqltext from v$sql where sql_id='aq03p7muwgvq5' and rownum<2; v_hints:=sys.sqlprof_attr( q'[BEGIN_OUTLINE_DATA]', q'[IGNORE_OPTIM_EMBEDDED_HINTS]', q'[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]', q'[DB_VERSION('11.2.0.4')], q'[ALL_ROWS]', q'[OUTLINE_LEAF(@"SEL$1")]', q'[FULL(@"SEL$1" "A"@"SEL$1")]', q'[END_OUTLINE_DATA]'); dbms_sqltune.import_sql_profile(v_sqltext,v_hints,'sql_full',force_match=>true,replace=>true); end;
作10053:orm
select value from v$parameter where name='sql_trace'; alter session set sql_trace=true; alter session set tracefile_identifier='mytrace';
--single instance
select tracefile from v$process where addr in (select paddr from v$session where sid in (select sid from v$Mystat where rownum<2));
--/u01/app/oracle/diag/rdbms/orcl/ORCL/trace/ORCL_ora_22354_mytrace.trc
ALTER SESSION SET EVENTS='10053 trace name context forever, level 1';
select * from a where object_id=3xml
/* Level 2:2級是1級的一個子集,它包含如下內容: Column statistics Single Access Paths Join Costs Table Joins Considered Join Methods Considered (NL/MS/HA) Level 1: 1級比2級更詳細,它包含2級的全部內容,在加以下內容: Parameters used by the optimizer Index statistics */
ALTER SESSION SET EVENTS '10053 trace name context off';
沒有看出什麼異常,和traceonly看到的一致,作sql_trace跟蹤sql_profile寫入的基表sys.sqlobj$data:
select to_char(comp_data),signature from sys.sqlobj$data where plan_Id=0
發現:
<outline_data <hint><![CDATA[BEGIN_OUTLINE_DATA]]></hint> <hint><![CDATA[IGNORE_OPTIM_EMBEDDED_HINTS]]></hint> <hint><![CDATA[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]]></hint> <hint><![CDATA[DB_VERSION('11.2.0.4')],q'[ALL_ROWS]]></hint> <hint><![CDATA[OUTLINE_LEAF(@"SEL$1")]]></hint> <hint><![CDATA[FULL(@"SEL$1" "A"@"SEL$1")]]></hint> <hint><![CDATA[END_OUTLINE_DATA]]></hint> </outline_data>
這一段裏,<hint><![CDATA[DB_VERSION('11.2.0.4')],q'[ALL_ROWS]]></hint>有點異常,刪除從新執行:
declare v_hints sys.sqlprof_attr; v_sqltext clob; begin select sql_fulltext into v_sqltext from v$sql where sql_id='aq03p7muwgvq5' and rownum<2; v_hints:=sys.sqlprof_attr( q'[BEGIN_OUTLINE_DATA]', q'[IGNORE_OPTIM_EMBEDDED_HINTS]', q'[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]', q'[ALL_ROWS]', q'[OUTLINE_LEAF(@"SEL$1")]', q'[FULL(@"SEL$1" "A"@"SEL$1")]', q'[END_OUTLINE_DATA]'); dbms_sqltune.import_sql_profile(v_sqltext,v_hints,'sql_full',force_match=>true,replace=>true); end;
正常:
Execution Plan ---------------------------------------------------------- Plan hash value: 2248738933 -------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | -------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 177 (1)| 00:00:01 | |* 1 | TABLE ACCESS FULL| A | 1 | 98 | 177 (1)| 00:00:01 | -------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("OBJECT_ID"=3) Note ----- - SQL profile "sql_full" used for this statement Statistics ---------------------------------------------------------- 1 recursive calls 0 db block gets 1248 consistent gets 1245 physical reads 0 redo size 1606 bytes sent via SQL*Net to client 519 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed