Oracle 12c 多租户：未完成事务的隐式提交（commit）

在前面的测试过程中，偶然发现12.1版本的一个表现，确切的说，应该是在12.1.0.1版本中。当关闭数据库前，当前会话中，未被提交的事务将会隐式被提交。

[oracle@12c01db trace]$ sqlplus / as sysdba
SQL*Plus: Release 12.1.0.1.0 Production on Thu Dec 1 16:48:42 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> select con_id,name,open_mode from v$pdbs;
    CON_ID NAME 			  OPEN_MODE
---------- ------------------------------ ----------
	 2 PDB$SEED			  READ ONLY
	 3 YHEM 			  MOUNTED
SQL> alter session set container=YHEM;
Session altered.
SQL> startup
Pluggable Database opened.
SQL> alter session set current_schema=EYGLE;
Session altered.
SQL> create table enmotech as select con_id,name,open_mode from v$pdbs;
Table created.
SQL> select * from enmotech;
    CON_ID NAME 			  OPEN_MODE
---------- ------------------------------ ----------
	 3 YHEM 			  READ WRITE
SQL> update enmotech set con_id=10000+con_id;
1 row updated.
SQL> select * from enmotech;
    CON_ID NAME 			  OPEN_MODE
---------- ------------------------------ ----------
     10003 YHEM 			  READ WRITE
SQL> shutdown immediate;
Pluggable Database closed.

正常情况下,这个未完成的事务应当被回滚。

SQL> connect / as sysdba
Connected.
SQL> alter pluggable database yhem open;
Pluggable database altered.
SQL> alter session set container=YHEM;
Session altered.
SQL> select * from eygle.enmotech;
    CON_ID NAME 			  OPEN_MODE
---------- ------------------------------ ----------
     10003 YHEM 			  READ WRITE

在12.1.0.2中已经改变。注意在以下的测试中，直接关闭PDB，Oracle会提示事务在进行中，需要提交或者回滚。此时abort命令拥有了进一步的实质性含义，不再提示，直接停止了PDB。当然最后事务被成功回退。

[oracle@enmocoredb ~]$ sqlplus / as sysdba
SQL*Plus: Release 12.1.0.2.0 Production on Thu Dec 1 17:06:53 2016
Copyright (c) 1982, 2014, Oracle.  All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> col name for a30
SQL> select con_id,name,open_mode from v$pdbs;
    CON_ID NAME 			  OPEN_MODE
---------- ------------------------------ --------------------
	 2 PDB$SEED			  READ ONLY
	 3 PDBPROD1			  READ WRITE
	 4 PDBPROD2			  MOUNTED
SQL> alter session set container=PDBPROD1;
Session altered.
SQL> create table enmotech as select con_id,name from v$pdbs;
Table created.
SQL> select * from enmotech;
    CON_ID NAME
---------- ------------------------------
	 3 PDBPROD1
SQL> update enmotech set con_id=10000+con_id;
1 row updated.
SQL> select * from enmotech;
    CON_ID NAME
---------- ------------------------------
     10003 PDBPROD1
SQL> shutdown immediate;
ORA-01097: cannot shutdown while in a transaction - commit or rollback first
SQL> shutdown abort;
Pluggable Database closed.
SQL> startup
Pluggable Database opened.
SQL> select * from enmotech;
    CON_ID NAME
---------- ------------------------------
	 3 PDBPROD1

一个新特性的引入，往往是牵一发动全身的改变，完善就需要从头再来。