测试目的： hint和手工指定OUTLINE参数的方式来帮顶执行计划，谁的优先级高？
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固定执行计划-使用SQL Tuning Advisor
固定执行计划-手工指定PLAN OUTLINE
固定执行计划-手工指定索引名称的方式
固定执行计划-使用coe_xfr_sql_profile固定执行计划
固定执行计划-使用SPM（Sql Plan Management）固定执行计划
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由于上一个测试中，已经绑定了sql使用SQL Tuning Advisor中的执行计划，从而使SQL走索引了（覆盖了hint）。这里我们需要先删除该SQL Profile，再手工绑定试试。
确认下SQL PROFILE的内容：
LUNAR@lunardb>SELECT * FROM DBA_SQL_PROFILES;NAME CATEGORY SIGNATURE------------------------------ ------------------------------ ----------------SQL_TEXT--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------CREATED LAST_MODIFIED--------------------------------------------------------------------------- ---------------------------------------------------------------------------DESCRIPTION--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------TYPE STATUS FOR TASK_ID TASK_EXEC_NAME TASK_OBJ_ID TASK_FND_ID TASK_REC_ID------- -------- --- ---------------- ------------------------------ ---------------- ---------------- ----------------SYS_SQLPROF_015236655fb80000 DEFAULT 6.5941520220E+17select /*+ no_index(lunartest1 idx_lunartest1_n) */ * from lunartest1 where n=112-JAN-16 10.12.39.000000 AM 12-JAN-16 10.12.39.000000 AMMANUAL ENABLED NO 158 EXEC_146 1 1 1Elapsed: 00:00:00.02LUNAR@lunardb>LUNAR@lunardb>SELECT extractValue(value(h),'.') AS hint 2 FROM sys.sqlobj$data od, sys.sqlobj$ so, 3 table(xmlsequence(extract(xmltype(od.comp_data),'/outline_data/hint'))) h 4 WHERE so.name = 'SYS_SQLPROF_015236655fb80000' 5 AND so.signature = od.signature 6 AND so.category = od.category 7 AND so.obj_type = od.obj_type 8 AND so.plan_id = od.plan_id;HINT--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------COLUMN_STATS("LUNAR"."LUNARTEST1", "N", scale, length=3 distinct=10000 nulls=0 min=1 max=10000)TABLE_STATS("LUNAR"."LUNARTEST1", scale, blocks=20 rows=10000)OPTIMIZER_FEATURES_ENABLE(default)IGNORE_OPTIM_EMBEDDED_HINTSElapsed: 00:00:00.05LUNAR@lunardb> |
这里我们看到该SQP Profile中提供了详细的表和列的统计信息
并且有“IGNORE_OPTIM_EMBEDDED_HINTS”，也就是忽略嵌入到SQL中的hint
确认一下，当前SQL语句使用了该SQL Profile：
LUNAR@lunardb>select * from table(dbms_xplan.display_cursor('bjgduva68mbqm',null,'outline'));PLAN_TABLE_OUTPUT--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------SQL_ID bjgduva68mbqm, child number 0-------------------------------------select /*+ no_index(lunartest1 idx_lunartest1_n) */ * from lunartest1where n=1Plan hash value: 3241900148-------------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |-------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | | | 1 (100)| ||* 1 | INDEX RANGE SCAN| IDX_LUNARTEST1_N | 1 | 3 | 1 (0)| 00:00:01 |-------------------------------------------------------------------------------------Outline Data------------- /*+ 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(@"SEL$1" "LUNARTEST1"@"SEL$1" ("LUNARTEST1"."N")) END_OUTLINE_DATA */Predicate Information (identified by operation id):--------------------------------------------------- 1 - access("N"=1)Note----- - SQL profile SYS_SQLPROF_015236655fb80000 used for this statement37 rows selected.Elapsed: 00:00:00.23LUNAR@lunardb> |
这里我们看到，当前执行确实使用了SQL profile SYS_SQLPROF_015236655fb80000，因此hint no_index失效了
（优先级低于SYS_SQLPROF_015236655fb80000，具体参见固定执行计划-使用SQL Tuning Advisor）
查看SYS_SQLPROF_015236655fb80000的OUTLINE信息：
LUNAR@lunardb>select '''' || extractvalue(value(d), '/hint') || ''',' as outline_hints 2 from xmltable('/*/outline_data/hint' passing ( 3 select xmltype(other_xml) as xmlval 4 from v$sql_plan 5 where sql_id = 'bjgduva68mbqm' and plan_hash_value = '3241900148' and other_xml is not null 6 ) 7 ) d;OUTLINE_HINTS--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------'IGNORE_OPTIM_EMBEDDED_HINTS','OPTIMIZER_FEATURES_ENABLE('11.2.0.4')','DB_VERSION('11.2.0.4')','ALL_ROWS','OUTLINE_LEAF(@"SEL$1")','INDEX(@"SEL$1" "LUNARTEST1"@"SEL$1" ("LUNARTEST1"."N"))',6 rows selected.Elapsed: 00:00:00.06LUNAR@lunardb> |
这里我们看到该SQP Profile中提供了详细的表和列的统计信息
并且有“IGNORE_OPTIM_EMBEDDED_HINTS”，也就是忽略嵌入到SQL中的hint
现在，我们删除这个SQL Profile，稍后使用上面的OUTLINE手工绑定执行计划：
LUNAR@lunardb>begin 2 DBMS_SQLTUNE.DROP_SQL_PROFILE(name => 'SYS_SQLPROF_015236655fb80000'); 3 end; 4 /PL/SQL procedure successfully completed.Elapsed: 00:00:00.02LUNAR@lunardb>SELECT * FROM DBA_SQL_PROFILES;no rows selectedElapsed: 00:00:00.00LUNAR@lunardb> |
此时，应该正常按照hint走了全表扫描：
LUNAR@lunardb>set autotrace traceonly exp statLUNAR@lunardb>select /*+ no_index(lunartest1 idx_lunartest1_n) */ * from lunartest1 where n=1;Elapsed: 00:00:00.03Execution Plan----------------------------------------------------------Plan hash value: 1172089107--------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |--------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | 4 | 7 (0)| 00:00:01 ||* 1 | TABLE ACCESS FULL| LUNARTEST1 | 1 | 4 | 7 (0)| 00:00:01 |--------------------------------------------------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - filter("N"=1)Statistics---------------------------------------------------------- 114 recursive calls 0 db block gets 137 consistent gets 0 physical reads 0 redo size 519 bytes sent via SQL*Net to client 524 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 15 sorts (memory) 0 sorts (disk) 1 rows processedLUNAR@lunardb> |
手工指定sqlprofile参数的方式绑定执行计划：
LUNAR@lunardb>declare 2 v_hints sys.sqlprof_attr; 3 sql_txt clob; 4 begin 5 v_hints:=sys.sqlprof_attr( 6 'BEGIN_OUTLINE_DATA', 7 'IGNORE_OPTIM_EMBEDDED_HINTS', 8 'OPTIMIZER_FEATURES_ENABLE(''11.2.0.4'')', 9 'DB_VERSION(''11.2.0.4'')', 10 'ALL_ROWS', 11 'OUTLINE_LEAF(@"SEL$1")', 12 'INDEX(@"SEL$1" "LUNARTEST1"@"SEL$1" ("LUNARTEST1"."N"))', 13 'END_OUTLINE_DATA' 14 ); 15 16 select sql_fulltext into sql_txt from v$sql where sql_id='&sqlid'; 17 dbms_sqltune.import_sql_profile(sql_text => sql_txt, 18 profile => v_hints,name => 'Lunar_Manaual_sqlprofile', 19 replace => TRUE,force_match => TRUE); 20 end; 21 /Enter value for sqlid: bjgduva68mbqmold 16: select sql_fulltext into sql_txt from v$sql where sql_id='&sqlid';new 16: select sql_fulltext into sql_txt from v$sql where sql_id='bjgduva68mbqm';PL/SQL procedure successfully completed.Elapsed: 00:00:00.53LUNAR@lunardb>LUNAR@lunardb>SELECT * FROM DBA_SQL_PROFILES;NAME CATEGORY SIGNATURE------------------------------ ------------------------------ ----------------SQL_TEXT--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------CREATED LAST_MODIFIED--------------------------------------------------------------------------- ---------------------------------------------------------------------------DESCRIPTION--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------TYPE STATUS FOR TASK_ID TASK_EXEC_NAME TASK_OBJ_ID TASK_FND_ID TASK_REC_ID------- -------- --- ---------------- ------------------------------ ---------------- ---------------- ----------------Lunar_Manaual_sqlprofile DEFAULT 9.9008162990E+18select /*+ no_index(lunartest1 idx_lunartest1_n) */ * from lunartest1 where n=112-JAN-16 10.44.30.000000 AM 12-JAN-16 10.44.30.000000 AMMANUAL ENABLED YESElapsed: 00:00:00.02LUNAR@lunardb> |
再次查询，看看Lunar_Manaual_sqlprofile是否生效：
LUNAR@lunardb>select /*+ no_index(lunartest1 idx_lunartest1_n) */ * from lunartest1 where n=1;Elapsed: 00:00:00.02Execution Plan----------------------------------------------------------Plan hash value: 3241900148-------------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |-------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | 4 | 1 (0)| 00:00:01 ||* 1 | INDEX RANGE SCAN| IDX_LUNARTEST1_N | 1 | 4 | 1 (0)| 00:00:01 |-------------------------------------------------------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - access("N"=1)Note----- - SQL profile "Lunar_Manaual_sqlprofile" used for this statementStatistics---------------------------------------------------------- 34 recursive calls 0 db block gets 13 consistent gets 1 physical reads 0 redo size 519 bytes sent via SQL*Net to client 524 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 1 rows processedLUNAR@lunardb> |
这里我们看到Lunar_Manaual_sqlprofile已经生效，且sql语句虽然带有no_index的hint，但是仍然可以按照SQL Profile指定的大纲使用索引
总结：
这里虽然有hint指定了no index，但是sql语句仍然按照Lunar_Manaual_sqlprofile指定的profile使用了index的
说明，使用手工指定outline参数的方式绑定的执行计划优先级高于hint
