分页SQL 的各种索引对比

SQL> 

select *
  from (select rownum as rn, a.*
          from (select *
                  from t100 a
                 where object_id > 1500
                   and owner = 'SYS'
                 order by object_id desc) a
         where rownum <= 40) a
 where rn >= 1;

SQL> select count(*) from t100;

  COUNT(*)
----------
  12083584

SQL> select count(*) from t100 where owner='SYS';


  COUNT(*)
----------
   4838784


SQL> select count(*)
                  from t100 a
                 where 
                 owner = 'SYS'
                 and object_name like '%LOG%'  2    3    4    5  ;

  COUNT(*)
----------
     37632


创建索引1：


  CREATE INDEX "SYSTEM"."T100_IDX1" ON "SYSTEM"."T100" ("OWNER", "OBJECT_ID") 



SQL> select *
  from (select rownum as rn, a.*
          from (select /*+ index(a t100_idx1)*/ *
                  from t100 a
                 where 
                    owner = 'SYS'
                    and object_name like 'LOG%'
                 order by object_id desc) a
         where rownum <= 40) a
 where rn >= 1;  2    3    4    5    6    7    8    9   10  

已选择40行。


执行计划
----------------------------------------------------------
Plan hash value: 3995274525

---------------------------------------------------------------------------------------------
| Id  | Operation			| Name	    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT		|	    |	  7 |  1540 |	432K  (1)| 01:26:36 |
|*  1 |  VIEW				|	    |	  7 |  1540 |	432K  (1)| 01:26:36 |
|*  2 |   COUNT STOPKEY 		|	    |	    |	    |		 |	    |
|   3 |    VIEW 			|	    |	  7 |  1449 |	432K  (1)| 01:26:36 |
|*  4 |     SORT ORDER BY STOPKEY	|	    |	  7 |	679 |	432K  (1)| 01:26:36 |
|*  5 |      TABLE ACCESS BY INDEX ROWID| T100	    |	  7 |	679 |	432K  (1)| 01:26:36 |
|*  6 |       INDEX RANGE SCAN		| T100_IDX1 |	431K|	    |  1318   (1)| 00:00:16 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=1)
   2 - filter(ROWNUM<=40)
   4 - filter(ROWNUM<=40)
   5 - filter("OBJECT_NAME" LIKE 'LOG%')
   6 - access("OWNER"='SYS')


统计信息
----------------------------------------------------------
	  1  recursive calls
	  0  db block gets
    4852145  consistent gets
     116880  physical reads
	  0  redo size
       2537  bytes sent via SQL*Net to client
	542  bytes received via SQL*Net from client
	  4  SQL*Net roundtrips to/from client
	  1  sorts (memory)
	  0  sorts (disk)
	 40  rows processed

逻辑读 4852145




创建索引2：

  CREATE INDEX "SYSTEM"."T100_IDX2" ON "SYSTEM"."T100" ("OWNER", "OBJECT_NAME", "OBJECT_ID") 

执行计划
----------------------------------------------------------
Plan hash value: 3889701471

---------------------------------------------------------------------------------------------
| Id  | Operation			| Name	    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT		|	    |	  7 |  1540 |	 13   (8)| 00:00:01 |
|*  1 |  VIEW				|	    |	  7 |  1540 |	 13   (8)| 00:00:01 |
|*  2 |   COUNT STOPKEY 		|	    |	    |	    |		 |	    |
|   3 |    VIEW 			|	    |	  7 |  1449 |	 13   (8)| 00:00:01 |
|*  4 |     SORT ORDER BY STOPKEY	|	    |	  7 |	679 |	 13   (8)| 00:00:01 |
|   5 |      TABLE ACCESS BY INDEX ROWID| T100	    |	  7 |	679 |	 12   (0)| 00:00:01 |
|*  6 |       INDEX RANGE SCAN		| T100_IDX2 |	  7 |	    |	  4   (0)| 00:00:01 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=1)
   2 - filter(ROWNUM<=40)
   4 - filter(ROWNUM<=40)
   6 - access("OWNER"='SYS' AND "OBJECT_NAME" LIKE 'LOG%')
       filter("OBJECT_NAME" LIKE 'LOG%')


统计信息
----------------------------------------------------------
	  1  recursive calls
	  0  db block gets
      10685  consistent gets
	  0  physical reads
	  0  redo size
       2537  bytes sent via SQL*Net to client
	542  bytes received via SQL*Net from client
	  4  SQL*Net roundtrips to/from client
	  1  sorts (memory)
	  0  sorts (disk)
	 40  rows processed


逻辑读 10685







创建索引3：

  CREATE INDEX "SYSTEM"."T100_IDX3" ON "SYSTEM"."T100" ("OBJECT_ID", "OWNER") 

执行计划
----------------------------------------------------------
Plan hash value: 1239817574

---------------------------------------------------------------------------------------------
| Id  | Operation			| Name	    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT		|	    |	  7 |  1540 |	468K  (1)| 01:33:43 |
|*  1 |  VIEW				|	    |	  7 |  1540 |	468K  (1)| 01:33:43 |
|*  2 |   COUNT STOPKEY 		|	    |	    |	    |		 |	    |
|   3 |    VIEW 			|	    |	  7 |  1449 |	468K  (1)| 01:33:43 |
|*  4 |     SORT ORDER BY STOPKEY	|	    |	  7 |	679 |	468K  (1)| 01:33:43 |
|*  5 |      TABLE ACCESS BY INDEX ROWID| T100	    |	  7 |	679 |	468K  (1)| 01:33:43 |
|*  6 |       INDEX FULL SCAN		| T100_IDX3 |	431K|	    | 36886   (1)| 00:07:23 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=1)
   2 - filter(ROWNUM<=40)
   4 - filter(ROWNUM<=40)
   5 - filter("OBJECT_NAME" LIKE 'LOG%')
   6 - access("OWNER"='SYS')
       filter("OWNER"='SYS')


统计信息
----------------------------------------------------------
	  1  recursive calls
	  0  db block gets
    4875771  consistent gets
     153771  physical reads
	  0  redo size
       2537  bytes sent via SQL*Net to client
	542  bytes received via SQL*Net from client
	  4  SQL*Net roundtrips to/from client
	  1  sorts (memory)
	  0  sorts (disk)
	 40  rows processed

逻辑读 4875771


创建索引4：

  CREATE INDEX "SYSTEM"."T100_IDX4" ON "SYSTEM"."T100" ("OBJECT_ID", "OWNER", "OBJECT_NAME") 

执行计划
----------------------------------------------------------
Plan hash value: 1079028630

---------------------------------------------------------------------------------------------
| Id  | Operation			| Name	    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT		|	    |	  7 |  1540 | 77998   (1)| 00:15:36 |
|*  1 |  VIEW				|	    |	  7 |  1540 | 77998   (1)| 00:15:36 |
|*  2 |   COUNT STOPKEY 		|	    |	    |	    |		 |	    |
|   3 |    VIEW 			|	    |	  7 |  1449 | 77998   (1)| 00:15:36 |
|*  4 |     SORT ORDER BY STOPKEY	|	    |	  7 |	679 | 77998   (1)| 00:15:36 |
|   5 |      TABLE ACCESS BY INDEX ROWID| T100	    |	  7 |	679 | 77997   (1)| 00:15:36 |
|*  6 |       INDEX FULL SCAN		| T100_IDX4 |	  7 |	    | 77989   (1)| 00:15:36 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=1)
   2 - filter(ROWNUM<=40)
   4 - filter(ROWNUM<=40)
   6 - access("OWNER"='SYS' AND "OBJECT_NAME" LIKE 'LOG%')
       filter("OWNER"='SYS' AND "OBJECT_NAME" LIKE 'LOG%')


统计信息
----------------------------------------------------------
	  1  recursive calls
	  0  db block gets
      89401  consistent gets
       2935  physical reads
	  0  redo size
       2537  bytes sent via SQL*Net to client
	542  bytes received via SQL*Net from client
	  4  SQL*Net roundtrips to/from client
	  1  sorts (memory)
	  0  sorts (disk)
	 40  rows processed

逻辑读: 89401

创建索引5：
  CREATE INDEX "SYSTEM"."T100_IDX5" ON "SYSTEM"."T100" ("OBJECT_NAME", "OWNER", "OBJECT_ID") 
执行计划
----------------------------------------------------------
Plan hash value: 3702588553

---------------------------------------------------------------------------------------------
| Id  | Operation			| Name	    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT		|	    |	  7 |  1540 |	 14   (8)| 00:00:01 |
|*  1 |  VIEW				|	    |	  7 |  1540 |	 14   (8)| 00:00:01 |
|*  2 |   COUNT STOPKEY 		|	    |	    |	    |		 |	    |
|   3 |    VIEW 			|	    |	  7 |  1449 |	 14   (8)| 00:00:01 |
|*  4 |     SORT ORDER BY STOPKEY	|	    |	  7 |	679 |	 14   (8)| 00:00:01 |
|   5 |      TABLE ACCESS BY INDEX ROWID| T100	    |	  7 |	679 |	 13   (0)| 00:00:01 |
|*  6 |       INDEX RANGE SCAN		| T100_IDX5 |	  7 |	    |	  5   (0)| 00:00:01 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=1)
   2 - filter(ROWNUM<=40)
   4 - filter(ROWNUM<=40)
   6 - access("OBJECT_NAME" LIKE 'LOG%' AND "OWNER"='SYS')
       filter("OWNER"='SYS' AND "OBJECT_NAME" LIKE 'LOG%')


统计信息
----------------------------------------------------------
	  0  recursive calls
	  0  db block gets
      10898  consistent gets
	  0  physical reads
	  0  redo size
       2537  bytes sent via SQL*Net to client
	542  bytes received via SQL*Net from client
	  4  SQL*Net roundtrips to/from client
	  1  sorts (memory)
	  0  sorts (disk)
	 40  rows processed