在Oracle9i中，使用External Table和动态SQL，在线地查看alter.log文件内容，从而进行某些查询、工作调度来监控错误。

使用下面的脚本可以实现上述的要求。

SQL> drop table e_alert_log;

Table dropped.

SQL> drop table t_perm_alert_log;

Table dropped.

SQL> drop table t_temp_alert_log;

Table dropped.

SQL> create or replace DIRECTORY alert_dir as 'D:oracleadminoracle9bdump';

Directory created.

SQL> create table e_alert_log

2 (detail_line VARCHAR2(2000)

3 ) ORGANIZATION EXTERNAL

4 (TYPE oracle_loader

5 DEFAULT DIRECTORY alert_dir

6 ACCESS PARAMETERS

7 ( RECORDS DELIMITED BY NEWLINE

8 nobadfile

9 nologfile

10 nodiscardfile

11 FIELDS TERMINATED by ' '

12 MISSING FIELD VALUES ARE NULL

13 (detail_line )

14 )

15 LOCATION('alert_oracle9.log') )

16 parallel 5

17 REJECT LIMIT UNLIMITED;

Table created.

SQL> create table t_perm_alert_log

2 (row_id number,

3 detail_line varchar2(2000) )

4 tablespace users

5 storage (initial 1m next 1m pctincrease 0);

Table created.

SQL>

SQL> create table t_temp_alert_log

2 (row_id number,

3 detail_line varchar2(2000) )

4 tablespace users

5 storage (initial 1m next 1m pctincrease 0);

Table created.

SQL>

SQL>

SQL> create or replace procedure update_alert as

2 BEGIN

3

4 -- This truncates the temp table from the last run...

5 execute immediate 'truncate table t_temp_alert_log';

6

7 -- Now, populate the temp table with all the alert log contents....

8 execute immediate 'insert into t_temp_alert_log select rownum,

9 detail_line from e_alert_log';

10

11 -- Now, populate the perm table with just the changes.....

12 execute immediate 'insert into t_perm_alert_log select row_id,

13 detail_line from t_temp_alert_log b

14 where b.row_id > (select nvl(max(a.row_id),0) from t_perm_alert_log a)';

15 END;

16 /

Procedure created.

SQL> exec update_alert

PL/SQL procedure successfully completed.

SQL> commit;

Commit complete.

SQL> select DETAIL_LINE from t_temp_alert_log sample(0.1) ;

DETAIL_LINE

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

ORA-12012: error on auto execute of job 1

Created Undo Segment _SYSSMU18$

Undo Segment 8 Offlined

3 rows selected.