利用外部表实现SQL查询Oracle告警日志Alert.log

本文根据刘相兵大师的blog的脚本，并做了一些该进：

http://www.oracledatabase12g.com/archives/%E5%88%A9%E7%94%A8%E5%A4%96%E9%83%A8%E8%A1%A8%E5%AE%9E%E7%8E%B0sql%E6%9F%A5%E8%AF%A2oracle%E5%91%8A%E8%AD%A6%E6%97%A5%E5%BF%97alert-log.html

有同学问是否可以用SQL语句直接查询告警日志的内容，即创建一张包含Alert.log内容的表或视图

--drop table alert_log_view;
--drop directory bdump;

declare
path_bdump varchar2(4000);
name_alert varchar2(4000);
ins_name varchar2(200);
begin

select value
into path_bdump
from sys.v_$parameter
where name = 'background_dump_dest';
select 'alert_' || value || '.log'
into name_alert
from sys.v_$parameter
where name = 'instance_name';

select value
into ins_name
from sys.v_$parameter
where name = 'instance_number';

if ins_name = '0' then
ins_name := '';
end if;

execute immediate 'create or replace directory bdump'||ins_name||' as ''' || path_bdump || '''';
execute immediate 'create table ALERT_LOG_VIEW' || ins_name ||
' (MSG_line varchar2(4000) ) ' ||
' organization external ' || ' (type oracle_loader ' ||
' default directory bdump' || ins_name ||
' access parameters ( ' ||
' records delimited by newline ' || ' nobadfile ' ||
' nologfile ' || ' nodiscardfile ' || ' skip 0 ' ||
' READSIZE 10485760 ' || ' FIELDS LDRTRIM ' ||
' REJECT ROWS WITH ALL NULL FIELDS ' ||
' (MSG_LINE (1:1000) CHAR(1000)) ' || ' ) ' ||
' location (''' || name_alert || ''') )' ||
' reject limit unlimited ' ||
' noparallel nomonitoring ';

end;
/
执行以上PL/SQL代码，会创建名为bdump$SID的目录 和ALERT_LOG_VIEW$SID的外部表(如RAC中的1号实例PROD1，则为ALERT_LOG_VIEW1,单实例single instance则为 ALERT_LOG_VIEW)， 需要时直接查询ALERT_LOG_VIEW即可，譬如要从告警信息中找出最近三天ORA-错误的记录:

col lineno noprint
col ora_error noprint
col msg_line format a132
set pages 0 lines 300 trimspool on trim on
alter session set nls_date_language = 'american';
alter session set nls_date_format='dd/mm/yyyy hh24:mi:ss';
alter session set sql_trace=false;
break on thedate
prompt
prompt ERROR IN ALERT LOG FILE - LAST 3 DAYS
prompt =====================================
select "LINENO", "THEDATE", "ORA_ERROR", "MSG_LINE"
from (select *
from (select lineno,
msg_line,
thedate,
max(case
when (ora_error like 'ORA-%' or
ora_error like 'PLS-%' or
ora_error like 'TNS-%'
)   then
rtrim(substr(ora_error, 1, instr(ora_error, ' ') - 1),
':')
else
null
end) over(partition by thedate) ora_error
from (select lineno,
msg_line,
max(thedate) over(order by lineno) thedate,
lead(msg_line) over(order by lineno) ora_error
from (select rownum lineno,
substr(msg_line, 1, 132) msg_line,
case
when msg_line like
'___ ___ __ __:__:__ ____' then
to_date(msg_line,
'Dy Mon DD hh24:mi:ss yyyy')
else
null
end thedate
from ALERT_LOG_VIEW))))
where ora_error is not null
and thedate >= (trunc(sysdate) - 3)
order by thedate
/

实例输出：

10/11/2011 03:15:49 Thu Nov 10 03:15:49 2011
Errors in file /s01/orabase/diag/rdbms/vprod/VPROD1/trace/VPROD1_ora_5547.trc (incident=11105):
ORA-00700: soft internal error, arguments: [kgerev1], [600], [600], [700], [], [], [], [], [], [], [], []
Incident details in: /s01/orabase/diag/rdbms/vprod/VPROD1/incident/incdir_11105/VPROD1_ora_5547_i11105.trc
Errors in file /s01/orabase/diag/rdbms/vprod/VPROD1/trace/VPROD1_ora_5547.trc (incident=11106):
ORA-00600: internal error code, arguments: [], [], [], [], [], [], [], [], [], [], [], []
Incident details in: /s01/orabase/diag/rdbms/vprod/VPROD1/incident/incdir_11106/VPROD1_ora_5547_i11106.trc
10/11/2011 03:15:52 Thu Nov 10 03:15:52 2011
Dumping diagnostic data in directory=[cdmp_20111110031552], requested by (instance=1, osid=5547), summary=[incident=11105].
 

有些情况下，我们的alert_log 是按天来开始备份的，这样我们可以通过下面的脚本，制定某个报警日志文件，来查询这个报警文件备份中的错误信息：

--drop table alert_log_view;
--drop directory bdump;

declare
path_bdump varchar2(4000);
name_alert varchar2(4000);
ins_name   varchar2(200);
begin

select value
into path_bdump
from sys.v_$parameter
where name = 'background_dump_dest';
select 'alert_' || value || '.log'
into name_alert
from sys.v_$parameter
where name = 'instance_name';

select value
into ins_name
from sys.v_$parameter
where name = 'instance_number';

if ins_name = '0' then
ins_name := '';
end if;

execute immediate 'create or replace directory bdump'||ins_name||' as ''' || path_bdump || '''';
execute immediate 'drop table alert_log_view'||ins_name||' purge';
execute immediate 'create table ALERT_LOG_VIEW' || ins_name ||
'  (MSG_line varchar2(4000)   ) ' ||
' organization external ' || ' (type oracle_loader ' ||
' default directory bdump' || ins_name ||
' access parameters ( ' ||
' records delimited by newline ' || ' nobadfile ' ||
' nologfile ' || ' nodiscardfile ' || ' skip 0 ' ||
' READSIZE 10485760 ' || ' FIELDS LDRTRIM ' ||
' REJECT ROWS WITH ALL NULL FIELDS ' ||
' (MSG_LINE (1:1000) CHAR(1000)) ' || ' ) ' ||
' location (''&alert_log'') )' ||
' reject limit unlimited ' ||
' noparallel nomonitoring ';

end;
/