明天咱们来做一个应用 SqlPatch 固定执行打算的 TEST.
1. 做 TEST 用 TABLE.
create table tab2(c1 number, c2 number, c3 varchar2(10));
declare
a number;
begin
a := 1;
for i in 1 .. 50 loop
for j in 1 .. 100 loop
insert into tab2 values(a,j,'a');
commit;
a := a+1;
end loop;
end loop;
end;
/
create index ind2_2 on tab2(c2);
2. 察看 SQLPLAN
SQL> conn test/test
SQL> explain plan for select * from tab2 where c2=1;
解析されました。SQL> select * from table (dbms_xplan.display(format=>'advanced'));
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------
Plan hash value: 2156729920
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 5 (0)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| TAB2 | 50 | 450 | 5 (0)| 00:00:01 |
--------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1 / TAB2@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
FULL(@"SEL$1" "TAB2"@"SEL$1")
OUTLINE_LEAF(@"SEL$1")
ALL_ROWS
DB_VERSION('11.2.0.4')
OPTIMIZER_FEATURES_ENABLE('11.2.0.4')
IGNORE_OPTIM_EMBEDDED_HINTS
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("C2"=1)
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - "TAB2"."C1"[NUMBER,22], "C2"[NUMBER,22], "TAB2"."C3"[VARCHAR2,10]
37 行が選択されました。3. 通过 Hint 做成应用 Index Scan 的 SQLPLAN
SQL> explain plan for select /*+ index(tab2 ind2_2) */ * from tab2 where c2=1;
解析されました。SQL> select * from table (dbms_xplan.display(format=>'advanced'));
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------
Plan hash value: 3201770281
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 11 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TAB2 | 50 | 450 | 11 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND2_2 | 50 | | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1 / TAB2@SEL$1
2 - SEL$1 / TAB2@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
INDEX_RS_ASC(@"SEL$1" "TAB2"@"SEL$1" ("TAB2"."C2"))
OUTLINE_LEAF(@"SEL$1")
ALL_ROWS
DB_VERSION('11.2.0.4')
OPTIMIZER_FEATURES_ENABLE('11.2.0.4')
IGNORE_OPTIM_EMBEDDED_HINTS
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("C2"=1)
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - "TAB2"."C1"[NUMBER,22], "C2"[NUMBER,22], "TAB2"."C3"[VARCHAR2,10]
2 - "TAB2".ROWID[ROWID,10], "C2"[NUMBER,22]
40 行が選択されました。4. 把 Hint“INDEX_RS_ASC(@”SEL$1″ “TAB2″@”SEL$1” (“TAB2”.”C2″))”作成 SqlPatch。
SQL> connect / as sysdba
SQL> begin
dbms_sqldiag_internal.i_create_patch (
sql_text => 'select * from tab2 where c2=1',
hint_text => 'INDEX_RS_ASC(@"SEL$1""TAB2"@"SEL$1" ("TAB2"."C2"))',
name => 'test patch'
);
end;
/ 2 3 4 5 6 7 8
PL/SQL プロシージャが失常に完了しました。5. 看看后果。
SQL> conn test/test
SQL> set lin 120 pages 999
SQL> set autot on explain
SQL> select * from tab2 where c2=1;
C1 C2 C3
---------- ---------- ------------------------------
601 1 a
... ...
4101 1 a
50 行が選択されました。実行計画
----------------------------------------------------------
Plan hash value: 3201770281
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 11 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TAB2 | 50 | 450 | 11 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND2_2 | 50 | | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("C2"=1)
Note
-----
- SQL patch "test patch" used for this statement