如何查看数据库alert日志文件

1、查看操作系统版本
sql> select * from v$version;
banner
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oracle database 10g enterprise edition release 10.2.0.1.0 - prod
pl/sql release 10.2.0.1.0 - production
core 10.2.0.1.0 production
tns for linux: version 10.2.0.1.0 - production
nlsrtl version 10.2.0.1.0 - production
sql>

2、查看预警日志文件（alert_sid.log）的位置
sql> show parameter dump
name type value
------------------------------------ ----------- ------------------------------
background_core_dump string partial
background_dump_dest string /u01/oracle/admin/bdump
core_dump_dest string /u01/oracle/admin/cdump
max_dump_file_size string 10240
shadow_core_dump string partial
user_dump_dest string /u01/oracle/admin/udump

3、创建目录alert
注意：directory不是实体，只是一个指向，指向os中一个路径
sql> create or replace directory alert as '/u01/oracle/admin/bdump';
directory created.
sql>

4、创建外部表alert
sql> create table alert
1 (log varchar2(1000))
2 organization external
3 (type oracle_loader
4 default directory alert
5 access parameters
6 (records delimited by newline)
7 location ('alert_prod.log'))
8 reject limit unlimited;
table created.

5、查看alert中的内容
sql> select * from alert where rownum<20;
log
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
wed feb 27 11:05:11 2013
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/:/ade/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
unable to find dynamic library libocrutl10.so in search paths
license_max_session = 0
license_sessions_warning = 0
picked latch-free scn scheme 2
using log_archive_dest_1 parameter default value as /u01/oracle/product/10.2.0/db_1/dbs/arch
autotune of undo retention is turned on.
imode=br
ilat =10
license_max_users = 0
sys auditing is disabled
19 rows selected.
sql>

6、看看数据库有哪些 可爱的ora- 错误吧
sql> select * from alert where log like '%ora-%';
log
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ora-959 signalled during: alter database default tablespace users...
ora-959 signalled during: drop tablespace uses...
ora-12919 signalled during: drop tablespace users...
ora-1549 signalled during: drop tablespace users...
ora-1505 signalled during: alter database add logfile group 1
ora-1184 signalled during: alter database add logfile group 1
ora-1013 signalled during: alter tablespace tts read only...
ora-1013 signalled during: alter tablespace tts read only...
ora-1013 signalled during: alter tablespace users read only...
ora-1539 signalled during: alter tablespace users read only...