2015年Oracle认证考试辅导：使用外部表查看ORACLE报警日志
发布时间：2010/3/13 11:34:39 来源：城市学习网 编辑：MOON
目得：首先了解什么是外部表，与其它表的区别，建立一个简单的外部表（主要看操作过程），最后我们用外部表查看ORACLE报警日志
外部表定义：结构被存放在数据字典，而表数据被放在OS文件中的表
作用：在数据库中查询OS文件的数据，还可以将OS文件数据装载到数据库中
与其它表的区别：在外部表上不能执行DML操作，也不能在外部表上建索引，只能执行select操用
1．建一个OS上的文件
因为外部表主要是查看OS上的文件，首先在OS上建一个文件
mkdir -p /oracle/ext
vi /oracle/ext/ext.dat
10，20，30
40，50，60
70，80，90
2．授予用户权限，并建立目录对象
在此我们先建一个新用户
create user test identified by “123” default tablespace test quota unlimited on test;
用户授权
SQL grant create any directory to test;
建立目录对象
SQL conn test / 123
Connected.
SQL create directory ext as ‘/oracle/ext‘;
Directory created.
3.建立外部表
SQL create table exttable(
id number，name varchar2(10)，i number
)organization external
(type oracle_loader
default directory ext
access parameters
(records delimited by newline
fields terminated by ‘，‘
)location(‘ext.dat‘)
);
4.测试
SQL select * from exttable;
ID NAME I
10 20 30
40 50 60
70 80 90
测试成功，可见在数据库中可以查询OS文件的数据
由于在上面实验中已建立了一个用户，并赋相应的权限，而且也有了OS文件(即报警文件alert_SID.log)，所以在此直接建立目录对象并建立外部表就可以了。
1．建立目录对象
SQL conn test / 123
Connected.
SQL create directory bdump as ‘/oracle/u01/app/oracle/admin/db2/bdump‘;
Directory created.
2．建立外部表
SQL create table alert_log(
text varchar2(400)
)organization external
(type oracle_loader
default directory bdump
access parameters
(records delimited by newline
)location(‘alert_db2.log‘)
);
3．测试
首先查看能否查到alert_db2.log的内容
SQL select * from alert_log where rownum 10;
TEXT
Thu Jun 11 00:51:46 2009
Starting ORACLE instance (normal)
Cannot determine all dependent dynamic libraries for /proc/self/exe
Unable to find dynamic library libocr10.so in search paths
RPATH = /ade/aime1_build2101/oracle/has/lib/:/ade/aime1_build2101/oracle/lib/:/a
de/aime1_build2101/oracle/has/lib/:
LD_LIBRARY_PATH is not set!
The default library directories are /lib and /usr/lib
Unable to find dynamic library libocrb10.so in search paths
Unable to find dynamic library libocrutl10.so in search paths
9 rows selected.
测试成功
然后我们测试查报警信息’ORA-%’
SQL select * from alert_log where text like ‘ORA-%‘;
TEXT
ORA-00202: control file: ‘/oracle/u01/app/oracle/product/10.2.0/db2/dbs/cntrldb2
.dbf‘
ORA-27037: unable to obtain file status
ORA-205 signalled during: ALTER DATABASE MOUNT...
ORA-00301: error in adding log file ‘/home/oracle/oracle/oradata/testdb/redo01.l
og‘file cannot be created
ORA-27040: file create error
ORA-1501 signalled during: CREATE DATABASE db2
ORA-00200: control file could not be created
TEXT
ORA-00202: control file: ‘/oracle/u01/app/oracle/product/10.2.0/db2/dbs/cntrldb2
.dbf‘
ORA-27038: created file already exists
ORA-1501 signalled during: CREATE DATABASE db2
ORA-00200: control file could not be created
ORA-00202: control file: ‘/oracle/u01/app/oracle/product/10.2.0/db2/dbs/cntrldb2
.dbf‘
ORA-27038: created file already exists
ORA-1501 signalled during: CREATE DATABASE db2
测试成功，
可见我们可以使用外部表来方便的查看ORACLE的报警信息.
