Oracle中如何追踪savepoint – Oracle数据库数据恢复、性能优化来问问AskMaclean – 诗檀软件旗下网站

Oracle中的savepoint是事务中的标示符，以帮助我们做到部分操作的回滚。

我们可以通过trace找出会话中自上次commit以来所有的savepoint保存点，要阅读这些trace内容你需要有user_dump_dest目录的相关权限。

SQL> oradebug setmypid;
已处理的语句
SQL>
SQL>
SQL> insert into  system.linktest values(2);

已创建 1 行。

SQL> savepoint a;

保存点已创建。

SQL> insert into system.linktest values(3);

已创建 1 行。

SQL> savepoint b;

保存点已创建。

SQL> insert into system.linktest values(4);

已创建 1 行。

SQL> savepoint d;

保存点已创建。

SQL> oradebug event immediate trace name savepoints level 1；

已处理的语句
SQL> oradebug tracefile_name;
e:\oracle\product\10.2.0\admin\orcln\udump\orcln_ora_1756.trc

其中 oradebug setmypid;  表示要trace的session为当前会话。

在非mts环境下，我们也可以通过如：

oradebug setospid OSPID;         — 通过指定OS中的进程号,即v$process中的spid

oradebug setorapid ORAPID;      — 通过指定Oracle 中的进程号，即v$process中的pid

来定制我们需要trace的相关session。

退回到命令行格式，该trace主要内容如下：

*** 2009-09-15 12:39:37.828
*** SERVICE NAME:(SYS$USERS) 2009-09-15 12:39:37.828
*** SESSION ID:(151.83) 2009-09-15 12:39:37.828
====================================================
SAVEPOINT FOR CURRENT PROCESS
——————————
flag: 0x1
name: D
dba: 0x800084, sequence #: 177, record #: 51, savepoint #: 81
status: VALID, next: 28236068
name: B
dba: 0x800084, sequence #: 177, record #: 50, savepoint #: 66
status: VALID, next: 282373F4
name: A
dba: 0x800084, sequence #: 177, record #: 49, savepoint #: 52
status: VALID, next: 00000000

metalink中的相关介绍如下：

Subject:	How To Find Out The Savepoint For Current Process
	Doc ID:	108611.1	Type:	BULLETIN
	Modified Date:	16-JUN-2004	Status:	PUBLISHED

PURPOSE

——-

This information shows you how to get the savepoints you have

issued since the last commit was issued.

SCOPE & APPLICATION

——————-

Any user can follow the steps to find out the savepoints in

their own session.  However, only the the user who have read

permission to the user_dump_dest directory can view the

output.

Steps to Retrieve the Savepoint Issued after the Last Commit

————————————————————

In the following illustration, two savepoints are created in

the same session.  Then a savepoints dump is issued to get

the savepoint information.  An example of the dump file is

included.

SQL> insert into emp (empno, ename)

2  values (9995, ‘vso’);

1 row created.

SQL> savepoint pt1;

Savepoint created.

SQL> insert into emp (empno, ename)

2  values (9994, ‘vso’);

1 row created.

SQL> savepoint pt2;

Savepoint created.

SQL> alter session set events

2  ‘immediate trace name savepoints level 1′;

Session altered.

A trace file is generated in the user_dump_directory.  The

content of the trace file is included in the following:

Dump file /u04/app/oracle/admin/R805/udump/r805_ora_18763.trc

Oracle8 Enterprise Edition Release 8.0.5.2.1 – Production

With the Partitioning and Objects options

PL/SQL Release 8.0.5.2.0 – Production

ORACLE_HOME = /u04/app/oracle/product/8.0.5

System name:    SunOS

Node name:      rtcsol1

Release:        5.6

Version:        Generic_105181-17

Machine:        sun4u

Instance name: R805

Redo thread mounted by this instance: 1

Oracle process number: 8

Unix process pid: 18763, image: oracleR805

*** 2000.04.18.14.11.37.000

*** SESSION ID:(7.391) 2000.04.18.14.11.37.000

====================================================

SAVEPOINT FOR CURRENT PROCESS

——————————

flag: 0x1

name: PT2

dba: 0x80020e, sequence #: 0, record #: 9, savepoint #: 131

status: VALID, next: 10a0868

name: PT1

dba: 0x80020e, sequence #: 0, record #: 7, savepoint #: 109

status: VALID, next: 0