我的oracle 9i学习日志（7）—诊断文件与练习3-原创手记-慕课网

诊断文件:包括数据库发生的重大事件的信息；用来帮助解决问题和更好的维护数据库。

类型：alertSID.log；后台跟踪文件（Background trace files）；用户跟踪文件（User trace files）。

1、以下操作或事件将被记录在alertSID.log文件：

数据库启动或关闭；

非默认值的参数列表（包括参数名称和参数值，在spfile或pfile损坏时可以借助这些信息从新构造spfile或pfile）；

启动后台进程；

被instance所用的线程；

The log sequence number LGWR is writing to；

有关log调整的信息；

创建表空间和undo segment；

已经提交的alter语句；

错误信息，如：ORA-600；

alter_SID.log所在位置由参数BACKGROUND_DUMP_DEST值定义。

2、后台跟踪文件（Background trace files）：

记录当后台程序出现重大错误时的信息。一般命名为sid_processname_PID.trc。所在位置由参数

BACKGROUND_DUMP_DEST值定义。

实验：

SQL> show parameter background_dump_dest

NAME TYPE VALUE

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

background_dump_dest string /u01/admin/lty/bdump

$ cd /u01/admin/lty/bdump

[oracle@localhost bdump]$ ls -l

total 828

-rw-r--r-- 1 oracle oinstall 142968 Mar 6 23:38 alert_lty.log

-rw-r----- 1 oracle oinstall 660699 Mar 3 17:11 lty_d000_3303.trc

-rw-r----- 1 oracle oinstall 779 Feb 23 09:59 lty_qmn0_3324.trc

-rw-r----- 1 oracle oinstall 802 Feb 23 10:05 lty_qmn0_3338.trc

-rw-r----- 1 oracle oinstall 803 Feb 23 10:10 lty_qmn0_3350.trc

3、用户跟踪文件（User trace files）:

由用户进程产生，也可以被server进程生成，包含跟踪SQL语句的统计信息和记录用户会话错误信息。可以用来对SQL的调优和排错。

命名规则一般为：sid_ora_PID.trc(如：db01_ora_23845.trc)，所处位置由参数USER_DUMP_DEST决定，文件大小由参数MAX_DUMP_FILE_SIZE决定。

启用和关闭用户跟踪

用户级别：ALTER SESSION SET SQL_TRACE = TRUE启用（注意：要在当前session设定）。也可以使用DBMS程序dbms_system.SET_SQL_TRACE_IN_SESSION。

instance级别：SQL_TRACE = TRUE启用（会产生大量信息记录，需谨慎）。

实验：

客户端：

sqlplus system/oracle@xxxx

SQL> alter session set sql_trace = true;

服务器：

$ ps -ef |grep oracle

oracle 3575 3574 0 00:57 ? 00:00:00 oraclelty (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

$cd /u01/admin/lty/udump

$ls –l

total 0

客户端：

SQL> select * from dual;

服务器：

$ls –l

total 4

-rw-r----- 1 oracle oinstall 1383 Mar 7 00:58 lty_ora_3575.trc

4、Practice 3: Managing an Oracle Instance

1 Connect to the database as user SYS and shut down the database.

2 With the database shut down, create an SPFILE from the PFILE. The SPFILE will be created in $ORACLE_HOME/dbs.

解析：SQL> create pfile from spfile;

3 From the operating system, view the SPFILE.

解析：

[oracle@localhost ~]$ cd dbs

[oracle@localhost dbs]$ ls -l

total 48

-rw-r--r-- 1 oracle oinstall 12920 Feb 22 20:14 initdw.ora

-rw-r--r-- 1 oracle oinstall 8475 Feb 22 20:14 init.ora

-rw-r----- 1 oracle oinstall 24 Mar 7 02:07 lkLTY

drwxr-xr-x 2 oracle oinstall 4096 Feb 22 16:29 old

-rwSr----- 1 oracle oinstall 1536 Feb 22 20:14 orapwlty

-rw-r----- 1 oracle oinstall 3584 Feb 22 20:14 spfilelty.ora

$strings spfilelty.ora

4 Connect as user SYS, and start the database using the SPFILE.

5 a Shut down the database and open it in read-only mode.

解析：SQL> startup mount

SQL> alter database open read only;

b Connect as user HR password HR and insert a row into the REGIONS table as

follows:

INSERT INTO regions VALUES (5, 'Mars');

What happens?

解析：HR默认为锁定状态，SQL> select username, user_id, account_status from dba_users;

USERNAME USER_ID ACCOUNT_STATUS

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

HR 47 EXPIRED & LOCKED

解锁，SQL> select username, account_status from dba_users;

USERNAME ACCOUNT_STATUS

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

HR EXPIRED

设置密码,SQL> alter user hr identified by hr;

查看状态，SQL> select username, account_status from dba_users;

USERNAME ACCOUNT_STATUS

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

HR OPEN

另创建用户lll密码lll，SQL> create user lll identified by lll;

以HR登陆后创建表lll,SQL> create table lll(num integer, name char(10));

插入行，SQL> insert into lll values(0, 'lll');

ERROR 位于第 1 行:

ORA-00604: error occurred at recursive SQL level 1

ORA-16000: database open for read-only access

c Put the database back in read-write mode.

6 a Connect as user HR password HR and insert the following row into the REGIONS

table; do not commit or exit.

INSERT INTO regions VALUES (5, 'Mars');

b In a new telnet session start SQL*Plus. Connect user SYS and perform

a SHUTDOWN TRANSACTIONAL.

c Roll back the insert in the HR session and exit.

What happens to the HR session?

What happens to the SYS session?

7 a In the user SYS session start the database.

b In the open telnet session start SQL*Plus and connect as user HR.

Note: Keep the two SQL*Plus sessions open, one session as user SYS and one as

user HR.

c As user SYS enable a restricted session.

d As user HR, SELECT from the REGIONS table. Is the SELECT successful?

e Exit the session, then reconnect as HR. What happens? The user HR does not have

RESTRICTED SESSION privilege, and therefore, cannot log in.

f As user SYS disable the restricted session.

g Exit the HR telnet session

解析：SQL> alter system enable restricted session;

在数据库置于restricted状态时，不会中断已连接用户的会话。

笔记oracle文件oracle技术