in-list扩展"inlistiterator""concatenation"

实验目的：IN-LIST中"inlist iterator" 与 "concatenation"区别，研究其中原理,进而对sql调优理解。注意连接词为含索引的列

成都做网站、成都网站建设、成都外贸网站建设,成都做网站公司-创新互联已向成百上千企业提供了,网站设计,网站制作,网络营销等服务!设计与技术结合,多年网站推广经验,合理的价格为您打造企业品质网站。

关键字： /*+USE_CONCAT */

SQL> SET LINESIZE 1000

SQL> SET LONG 9000

SQL> SET LONGCHUNKSIZE 1000

SQL> select * from user_indexes where table_name='T1';

INDEX_NAME INDEX_TYPE TABLE_OWNER TABLE_NAME TABLE_TYPE

UNIQUENESS COMPRESSION PREFIX_LENGTH TABLESPACE_NAME INI_TRANS

MAX_TRANS INITIAL_EXTENT NEXT_EXTENT MIN_EXTENTS MAX_EXTENTS PCT_INCREASE PCT_THRESHOLD INCLUDE_COLUMN FREELISTS FREELIST_GROUPS PCT_FREE LOGGIN BLEVEL LEAF_BLOCKS DISTINCT_KEYS AVG_LEAF_BLOCKS_PER_KEY AVG_DATA_BLOCKS_PER_KEY CLUSTERING_FACTOR STATUS NUM_ROWS SAMPLE_SIZE LAST_ANALYZED DEGREE

INSTANCES PARTIT TE GE SE BUFFER_POOL FLASH_CACHE CELL_FLASH_CAC USER_S DURATION PCT_DIRECT_ACCESS

------------------------------------------------------------ ------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ---------------------- ------------------ ---------------- ------------- ------------------------------------------------------------ ---------- ---------- -------------- ----------- ----------- ----------- ------------ ------------- -------------- ---------- --------------- ---------- ------ ---------- ----------- ------------- ----------------------- ----------------------- ----------------- ---------------- ---------- ----------- -------------- -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- ------ -- -- -- -------------- -------------- -------------- ------ ------------------------------ -----------------

ITYP_OWNER ITYP_NAME

------------------------------------------------------------ ------------------------------------------------------------

PARAMETERS

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

GLOBAL DOMIDX_STATUS DOMIDX_OPSTA FUNCIDX_STATUS JOIN_I IOT_RE DROPPE VISIBILITY DOMIDX_MANAGEMENT SEGMEN

------ ------------------------ ------------ ---------------- ------ ------ ------ ------------------ ---------------------------- ------

IDX_T1 NORMAL TEST

T1 TABLE

NONUNIQUE DISABLED TEST 2

255 65536 1048576 1 2147483645

10 YES 1 21 10000 1 1

16 VALID 10000 10000 27-3月 -18 1

1 NO N N N DEFAULT

DEFAULT DEFAULT NO

YES NO NO NO VISIBLE

YES

SQL> select * from t1 where n in (1,2,3);

----------

SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced'));

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

SQL_ID bkmtcvphbgw01, child number 0

-------------------------------------

select * from t1 where n in (1,2,3)

Plan hash value: 2105407043

----------------------------------------------------------------------------

----------------------------------------------------------------------------

| 0 | SELECT STATEMENT | | | | 3 (100)| |

| 1 | INLIST ITERATOR | | | | | |

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

|* 2 | INDEX RANGE SCAN| IDX_T1 | 3 | 12 | 3 (0)| 00:00:01 |

----------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

1 - SEL$1

2 - SEL$1 / T1@SEL$1

Outline Data

-------------

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

/*+

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" "T1"@"SEL$1" ("T1"."N"))

END_OUTLINE_DATA

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Predicate Information (identified by operation id):

---------------------------------------------------

2 - access(("N"=1 OR "N"=2 OR "N"=3))

Column Projection Information (identified by operation id):

-----------------------------------------------------------

1 - "N"[NUMBER,22]

2 - "N"[NUMBER,22]

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

已选择45行。

SQL> SELECT /*+USE_CONCAT */ * FROM T1 WHERE N IN(1,2,3);

----------

SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced')); --强制 HINT 失效

PLAN_TABLE_OUTPUT

SQL_ID 1fsdbt9t3hdwf, child number 0

-------------------------------------

SELECT /*+USE_CONCAT */ * FROM T1 WHERE N IN(1,2,3)

Plan hash value: 2105407043

----------------------------------------------------------------------------

----------------------------------------------------------------------------

| 0 | SELECT STATEMENT | | | | 3 (100)| |

| 1 | INLIST ITERATOR | | | | | |

PLAN_TABLE_OUTPUT

|* 2 | INDEX RANGE SCAN| IDX_T1 | 3 | 12 | 3 (0)| 00:00:01 |

----------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

1 - SEL$1

2 - SEL$1 / T1@SEL$1

Outline Data

-------------

PLAN_TABLE_OUTPUT

/*+

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" "T1"@"SEL$1" ("T1"."N"))

END_OUTLINE_DATA

PLAN_TABLE_OUTPUT

Predicate Information (identified by operation id):

---------------------------------------------------

2 - access(("N"=1 OR "N"=2 OR "N"=3))

Column Projection Information (identified by operation id):

-----------------------------------------------------------

1 - "N"[NUMBER,22]

2 - "N"[NUMBER,22]

PLAN_TABLE_OUTPUT

已选择45行。

SQL> exec dbms_stats.gather_table_stats(ownname =>'TEST',tabname =>'T1',cascade => TRUE,method_opt =>'FOR ALL COLUMNS SIZE 1' ,no_invalidate => false ); --使共享游标失效，重新生成SQL计划

PL/SQL 过程已成功完成。

SQL> select * from t1 where n in (1,2,3);

----------

SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced'));

PLAN_TABLE_OUTPUT

SQL_ID bkmtcvphbgw01, child number 0

-------------------------------------

select * from t1 where n in (1,2,3)

Plan hash value: 4271029992

----------------------------------------------------------------------------

----------------------------------------------------------------------------

| 0 | SELECT STATEMENT | | | | 3 (100)| |

| 1 | CONCATENATION | | | | | |

PLAN_TABLE_OUTPUT

|* 2 | INDEX RANGE SCAN| IDX_T1 | 1 | 4 | 1 (0)| 00:00:01 |

|* 3 | INDEX RANGE SCAN| IDX_T1 | 1 | 4 | 1 (0)| 00:00:01 |

|* 4 | INDEX RANGE SCAN| IDX_T1 | 1 | 4 | 1 (0)| 00:00:01 |

----------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

1 - SEL$1

2 - SEL$1_1 / T1@SEL$1

3 - SEL$1_2 / T1@SEL$1_2

PLAN_TABLE_OUTPUT

4 - SEL$1_3 / T1@SEL$1_3

Outline Data

-------------

/*+

BEGIN_OUTLINE_DATA

IGNORE_OPTIM_EMBEDDED_HINTS

OPTIMIZER_FEATURES_ENABLE('11.2.0.4')

DB_VERSION('11.2.0.4')

ALL_ROWS

PLAN_TABLE_OUTPUT

OUTLINE_LEAF(@"SEL$1")

OUTLINE_LEAF(@"SEL$1_1")

USE_CONCAT(@"SEL$1" 8 OR_PREDICATES(1))

OUTLINE_LEAF(@"SEL$1_2")

OUTLINE_LEAF(@"SEL$1_3")

OUTLINE(@"SEL$1")

INDEX(@"SEL$1_1" "T1"@"SEL$1" ("T1"."N"))

INDEX(@"SEL$1_2" "T1"@"SEL$1_2" ("T1"."N"))

INDEX(@"SEL$1_3" "T1"@"SEL$1_3" ("T1"."N"))

END_OUTLINE_DATA

PLAN_TABLE_OUTPUT

Predicate Information (identified by operation id):

---------------------------------------------------

2 - access("N"=3)

3 - access("N"=2)

4 - access("N"=1)

Column Projection Information (identified by operation id):

-----------------------------------------------------------

PLAN_TABLE_OUTPUT

1 - "T1".ROWID[ROWID,10], "N"[NUMBER,22]

2 - "T1".ROWID[ROWID,10], "N"[NUMBER,22]

3 - "T1".ROWID[ROWID,10], "N"[NUMBER,22]

4 - "T1".ROWID[ROWID,10], "N"[NUMBER,22]

已选择60行。

网站栏目：in-list扩展"inlistiterator""concatenation"
当前URL：http://cdxtjz.cn/article/ggsdsd.html

in-list扩展"inlistiterator""concatenation"

其他资讯