ORACLE SQL优化 - ORACLE执行计划

Last login: Mon Feb 8 14:13:19 2010 from 192.168.1.249

ipnet
-bash-3.00$
-bash-3.00$ ipnet
-bash: ipnet: command not found
-bash-3.00$ su - oracle
Password:
eastcsu: incorrect password
-bash-3.00$ eastcom
-bash: eastcom: command not found
-bash-3.00$ su - oracle
Password:
[oracle@ipnet-td2 ~]$

[oracle@ipnet-td2 ~]$ sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Feb 8 14:14:08 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

SQL> su^H^H^H
SP2-0042: unknown command " - rest of line ignored.
SQL> conn ipnet/ipnet1234@ORAC^H^H^H
ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified

SQL> ^[[A^H " - rest of line ignored.
SQL> 042: unknown command "
SQL> conn ipnet/ipnet1234@ORCL
Connected.
SQL> set timn^H
SP2-0158: unknown SET option "tim"
SQL> set timing on
SQL> set autot traceonly
SQL> select v.NAME_CN from vendor v, vendordevicetype vt, devicetype t where t.name = vt.device_type_name and v.name = vt.vendor_name and t.name_cn = '防火墙';

Elapsed: 00:00:00.01

Execution Plan
----------------------------------------------------------
Plan hash value: 497066359

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

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

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

| 0 | SELECT STATEMENT | | 5 | 205 | 7
(0)| 00:00:01 |

| 1 | NESTED LOOPS | | 5 | 205 | 7
(0)| 00:00:01 |

| 2 | NESTED LOOPS | | 5 | 140 | 4
(0)| 00:00:01 |

|* 3 | TABLE ACCESS FULL | DEVICETYPE | 1 | 14 | 3
(0)| 00:00:01 |

| 4 | TABLE ACCESS BY INDEX ROWID| VENDORDEVICETYPE | 5 | 70 | 1
(0)| 00:00:01 |

|* 5 | INDEX RANGE SCAN | N907275051_IDX | 5 | | 0
(0)| 00:00:01 |

| 6 | TABLE ACCESS BY INDEX ROWID | VENDOR | 1 | 13 | 1
(0)| 00:00:01 |

|* 7 | INDEX UNIQUE SCAN | NAME_4_1 | 1 | | 0
(0)| 00:00:01 |

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

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

3 - filter("T"."NAME_CN"='防火墙')
5 - access("T"."NAME"="VT"."DEVICE_TYPE_NAME")
7 - access("V"."NAME"="VT"."VENDOR_NAME")

Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
18 consistent gets
0 physical reads
0 redo size
466 bytes sent via SQL*Net to client
385 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
3 rows processed

SQL>