背景：
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Oracle全文索引的性能优势实例
[日期：2014-10-08] 来源：Linux公社 作者：Linux [字体：]
一、实验说明：
操作系统：rhel 5.4 x86
二、操作步骤：
2.1、首先创建一个表t_btree，并创建B-Tree索引，索引键是object_name:
SQL> create table t_btree as select * from dba_objects;
Table created.
SQL> create index ind_btree on t_btree(object_name);
Index created.
接着是执行下面的查询语句两次：
SQL> set linesize 150;
SQL> set autotrace on;
SQL> select count(*) from t_btree where t_btree.object_name like '%ObjectStreamClass%';
COUNT(*)
----------
84
Execution Plan
----------------------------------------------------------
Plan hash value: 3266099700
-----------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 66 | 103 (0)| 00:00:02 |
| 1 | SORT AGGREGATE | | 1 | 66 | | |
|* 2 | INDEX FAST FULL SCAN| IND_BTREE | 12 | 792 | 103 (0)| 00:00:02 |
-----------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - filter("T_BTREE"."OBJECT_NAME" IS NOT NULL AND
"T_BTREE"."OBJECT_NAME" LIKE '%ObjectStreamClass%')
Note
-----
- dynamic sampling used for this statement (level=2)
Statistics
----------------------------------------------------------
28 recursive calls
0 db block gets
454 consistent gets
726 physical reads
0 redo size
422 bytes sent via SQL*Net to client
419 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> select count(*) from t_btree where t_btree.object_name like '%ObjectStreamClass%';
COUNT(*)
----------
84
Execution Plan
----------------------------------------------------------
Plan hash value: 3266099700
-----------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 66 | 103 (0)| 00:00:02 |
| 1 | SORT AGGREGATE | | 1 | 66 | | |
|* 2 | INDEX FAST FULL SCAN| IND_BTREE | 12 | 792 | 103 (0)| 00:00:02 |
-----------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - filter("T_BTREE"."OBJECT_NAME" IS NOT NULL AND
"T_BTREE"."OBJECT_NAME" LIKE '%ObjectStreamClass%')
Note
-----
- dynamic sampling used for this statement (level=2)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
369 consistent gets
0 physical reads
0 redo size
422 bytes sent via SQL*Net to client
419 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
2.2、创建表t_bmap，并创建BitMap索引：