ORA-14450

ORA-14450 attempt to access a transactional temp table already in use

Cause: An attempt was made to access a transactional temporary table that has been already populated by a concurrent transaction of the same session.

Action: Do not attempt to access the temporary table until the concurrent transaction has committed or aborted.

一般情况下，ORA-14450在自治事务中出现的多一些，大家在使用自治事务时一定要小心

SQL> create global temporary table temp_toms
2 (
3 str varchar2(64)
4 ) on commit delete rows;

表已创建.

SQL>

SQL> select * from temp_toms;

未选定行

SQL> insert into temp_toms values('1234');

已创建 1 行。

SQL> select * from temp_toms;

STR
--------------------------------
1234

SQL> 
SQL> declare
2 pragma autonomous_transaction;
3 begin
4 insert into temp_toms values('other transaction use temp_toms test');
5 commit;
6 end;
7 /
declare
*
第 1 行出现错误:
ORA-14450: 试图访问已经在使用的事务处理临时表
ORA-06512: 在 line 4

SQL> select * from temp_toms;

STR
--------------------------------
1234

SQL>

另外一种情况下，也能出现ORA-14450的错误，测试如下

SQL> select sid from v$mystat where rownum=1;

SID
----------
104
SQL>

SQL> desc temp_toms
名称 是否为空? 类型
----------------------------------------- -------- -----------------
STR VARCHAR2(32)

SQL> insert into temp_toms values('modify structur test');

已创建 1 行。

SQL> 
SQL> select * from temp_toms;

STR
--------------------------------
modify structur test

SQL>

此时，在SID=104的session中不做commit/rollback，打开另外一个session，尝试修改临时表结构，
看看会出现什么现象：

C:Documents and Settingsunix>sqlplus study/study

SQL*Plus: Release 10.2.0.1.0 - Production on 星期六 5月 6 12:26:54 2006

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

连接到:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> select sid from v$mystat where rownum=1;

SID
----------
90

SQL>
SQL> alter table temp_toms add name varchar2(32);
alter table temp_toms add name varchar2(32)
*
第 1 行出现错误:
ORA-14450: 试图访问已经在使用的事务处理临时表