@ Dbsnake-Use appropriate function indexes to avoid seemingly unavoidable full table scans

Source: Internet
Author: User

Table created.

ID NAME
---------------
1 abc
2 bc
3 c

SQL> select id, name from rev where name like '% bc ';
ID NAME
---------------
1 abc
2 bc

Execution Plan
----------------------------------------------------------
Plan hash value: 3205185662


| Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |
--------------------------------------------------------------------------
| 0 | select statement | 2 | 34 | 3 (0) | 00:00:01 |
| * 1 | table access full | REV | 2 | 34 | 3 (0) | 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id ):
---------------------------------------------------
1-filter ("NAME" LIKE '% bc ')

Note
-----
-Dynamic sampling used for this statement

Statistics
----------------------------------------------------------
5 recursive cballs
0 db block gets
16 consistent gets
0 physical reads
0 redo size
633 bytes sent via SQL * Net to client
492 bytes encoded ed via SQL * Net from client
2 SQL * Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed

Index created.

ID NAME
---------------
2 bc
1 abc

Execution Plan
----------------------------------------------------------
Plan hash value: 2418054352

Bytes ---------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |

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

2-access (REVERSE ("NAME") LIKE 'cb % ')
Filter (REVERSE ("NAME") LIKE 'cb % ')

Note
-----
-Dynamic sampling used for this statement

Statistics
----------------------------------------------------------
28 recursive cballs
0 db block gets
14 consistent gets
0 physical reads
0 redo size
633 bytes sent via SQL * Net to client
492 bytes encoded ed via SQL * Net from client
2 SQL * Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed

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