透过V视图session,open_cursor,lock 诊断及定位问题根源

 

SELECT round(bitand(s.ownerid, 65535)) parent_session_sid,

round(bitand(s.ownerid,16711680)/65536) parent_session_instid, s.SADDR, s.SID,

s.SERIAL#, s.AUDSID, s.PADDR, s.USER#, s.USERNAME, s.COMMAND, s.OWNERID,

s.TADDR, s.LOCKWAIT, s.STATUS, s.SERVER, s.SCHEMA#, s.SCHEMANAME, s.OSUSER,

s.PROCESS, s.MACHINE, s.TERMINAL, UPPER(s.PROGRAM) PROGRAM, s.TYPE,

s.SQL_ADDRESS, s.SQL_HASH_VALUE, s.SQL_ID, s.SQL_CHILD_NUMBER, s.PREV_SQL_ADDR,

s.PREV_HASH_VALUE, s.PREV_SQL_ID, s.PREV_CHILD_NUMBER, s.PLSQL_ENTRY_OBJECT_ID,

s.PLSQL_ENTRY_SUBPROGRAM_ID, s.PLSQL_OBJECT_ID, s.PLSQL_SUBPROGRAM_ID, s.MODULE,

s.MODULE_HASH, s.ACTION, s.ACTION_HASH, s.CLIENT_INFO, s.FIXED_TABLE_SEQUENCE,

s.ROW_WAIT_OBJ#, s.ROW_WAIT_FILE#, s.ROW_WAIT_BLOCK#, s.ROW_WAIT_ROW#,

s.LOGON_TIME, s.LAST_CALL_ET, s.PDML_ENABLED, s.FAILOVER_TYPE,

s.FAILOVER_METHOD, s.FAILED_OVER, s.RESOURCE_CONSUMER_GROUP, s.PDML_STATUS,

s.PDDL_STATUS, s.PQ_STATUS, s.CURRENT_QUEUE_DURATION, s.CLIENT_IDENTIFIER,

s.BLOCKING_SESSION_STATUS, s.BLOCKING_INSTANCE, s.BLOCKING_SESSION, s.SEQ#,

s.EVENT#, s.EVENT, s.P1TEXT, s.P1, s.P1RAW, s.P2TEXT, s.P2, s.P2RAW, s.P3TEXT,

s.P3, s.P3RAW, s.WAIT_CLASS_ID, s.WAIT_CLASS#, s.WAIT_CLASS, s.WAIT_TIME,

s.SECONDS_IN_WAIT, s.STATE, s.SERVICE_NAME, s.SQL_TRACE, s.SQL_TRACE_WAITS,

s.SQL_TRACE_BINDS, stat.cpu - stat.CPU_this_call_start cpu_this_call, stat.CPU,

stat.UGA_memory, stat.PGA_memory, stat.Commits, stat.Rollbacks, si.Block_Gets,

si.Consistent_Gets, si.Physical_Reads, si.Block_Changes, si.Consistent_Changes FROM V$SESSION S, V$SESS_IO si,

(select ss.sid stat_sid,

sum(decode(sn.name, 'CPU used when call started', ss.value, 0))

CPU_this_call_start, sum(decode(sn.name, 'CPU used by this session', ss.value, 0)) CPU,

sum(decode(sn.name, 'session uga memory', ss.value, 0)) uga_memory,

sum(decode(sn.name, 'session pga memory', ss.value, 0)) pga_memory,

sum(decode(sn.name, 'user commits', ss.value, 0)) commits,

sum(decode(sn.name, 'user rollbacks', ss.value, 0)) rollbacks

from v$sesstat ss, v$statname sn

where ss.STATISTIC# = sn.STATISTIC#

and (sn.name = 'CPU used when call started' or

sn.name = 'CPU used by this session' or

sn.name = 'session uga memory' or

sn.name = 'session pga memory' or

sn.name = 'user commits' or

sn.name = 'user rollbacks')

group by ss.sid) stat

WHERE ( (s.USERNAME is not null) and (NVL(s.osuser,'x') <> 'SYSTEM') and

(s.type <> 'BACKGROUND') ) and (si.sid(+)=s.sid)

and (stat.stat_sid = s.sid)

--先用上面的查询列出当前session的状况

select p.spid thread_1,s.username,

decode(nvl(p.background,0),1,bg.description,

s.program ) program,

ss.value/100 CPU,physical_reads disk_io

from v$process p,

v$session s,

v$sesstat ss,

v$sess_io si,

v$bgprocess bg

where s.paddr=p.addr

and ss.sid=s.sid

and ss.statistic#=12

and si.sid=s.sid

and bg.paddr(+)=p.addr

order by ss.value desc;

--进程消耗的CPU,IO资源

select a.sid session_id,b.spid process_id

from v$session a,v$process b

where a.paddr = b.addr and a.sid = (select sid from v$mystat where rownum = 1);

--当前的session_id

SELECT S.USERNAME, P.SPID OS_PROCESS_ID, P.PID ORACLE_PROCESS_ID FROM V$SESSION S, V$PROCESS P WHERE S.PADDR = P.ADDR AND S.SID=227

--透过SESSION_ID 找process_ID

select

o.sid, o.sql_text, o.address, o.hash_value, o.user_name, s.schemaname

from v$open_cursor o, v$session s

where o.saddr = s.saddr

and o.sid = s.sid

and ( O.SID = '275')

--定位好session ID后,可以开始查看这个sid最近所open的游标,可以找到部分cursor

SELECT SQL_TEXT FROM V$SQLTEXT_WITH_NEWLINES WHERE

HASH_VALUE=TO_NUMBER('561877498') ORDER BY PIECE

--依靠hash_value可以继续往下定位详细的sql语句.

SELECT

SID, EVENT, TOTAL_WAITS, TOTAL_TIMEOUTS, TIME_WAITED, AVERAGE_WAIT

, MAX_WAIT

, TIME_WAITED_MICRO

FROM v$session_event

Where sid = '278'

ORDER BY SID, TIME_WAITED DESC

--依靠sid,可以抓取这个session最近的event时间总和

SELECT

SID, SEQ#, EVENT, WAIT_TIME, SECONDS_IN_WAIT, STATE, p1, p1text, p2,

p2text, p3, p3text FROM v$session_wait

WHERE sid = '278'

ORDER BY SID, SECONDS_IN_WAIT DESC

--这个是查找sid的wait event

SELECT LK.SID, SE.USERNAME, SE.OSUSER, SE.MACHINE, DECODE(LK.TYPE, 'TX', 'Transaction', 'TM', 'DML', 'UL', 'PL/SQL User Lock', LK.TYPE) LOCK_TYPE, DECODE(LK.LMODE, 0, 'None', 1, 'Null', 2, 'Row-S (SS)', 3, 'Row-X (SX)', 4, 'Share', 5, 'S/Row-X (SSX)', 6, 'Exclusive', TO_CHAR(LK.LMODE)) MODE_HELD, DECODE(LK.REQUEST, 0, 'None', 1, 'Null', 2, 'Row-S (SS)', 3, 'Row-X (SX)', 4, 'Share', 5, 'S/Row-X (SSX)', 6, 'Exclusive', TO_CHAR(LK.REQUEST)) MODE_REQUESTED, TO_CHAR(LK.ID1) LOCK_ID1, TO_CHAR(LK.ID2) LOCK_ID2, OB.OWNER, OB.OBJECT_TYPE, OB.OBJECT_NAME, DECODE(LK.BLOCK, 0, 'No', 1, 'Yes', 2, 'Global') BLOCK, SE.LOCKWAIT

FROM V$LOCK LK

INNER JOIN V$SESSION SE ON LK.SID = SE.SID

LEFT JOIN DBA_OBJECTS OB ON LK.ID1 = OB.OBJECT_ID

WHERE LK.TYPE IN ('TM', 'UL', 'TX')

AND (LK.SID = '278');

--当前sid的lock状况,当然啦,如果把最后的条件去掉,那就是当前数据库的全局lock状况.

SELECT * FROM v$session_longops;

--表扫描状态

/*******************************************************************/

/************************下面是trace部分****************************/

/*******************************************************************/

ALTER SESSION SET timed_statistics=true;

ALTER SESSION SET max_dump_file_size=unlimited;

ALTER SESSION SET tracefile_identifier='my_trace_session';

--几个相关的参数

--正常情况,一般都是直接上10046

ALTER SESSION SET EVENTS '10046 trace name context forever, level 12';

ALTER SESSION SET EVENTS '10046 trace name context off';

exec dbms_monitor.serv_mod_act_trace_enable(service_name=>' ', module_name=>' ');

--使用 SERVICE_NAME,module_name来跟踪

exec dbms_monitor.client_id_trace_enable(client_id=>' ');

-- 使用CLIENT_IDENTIFIER来跟踪

exec dbms_monitor.session_trace_enable(139);

--如果定位得到session_id的话,就可以直接依靠session_ID跟踪

CREATE OR REPLACE TRIGGER trace_test_user AFTER LOGON ON DATABASE

BEGIN

IF USER LIKE '%\_test' ESCAPE '\' THEN

EXECUTE IMMEDIATE 'ALTER SESSION SET timed_statistics=true';

EXECUTE IMMEDIATE 'ALTER SESSION SET max_dump_file_size=unlimited';

EXECUTE IMMEDIATE 'ALTER SESSION SET EVENTS ''10046 trace name context forever, level 8'' ';

END IF;

END;

/

-- 代码来自《Optimazing Oracle Performance》 P116

--触发器来做trace,一般属于最后的杀手锏.

/***********通过OS PID,使用oradebug来做trace**************/

SELECT S.USERNAME,

P.SPID OS_PROCESS_ID,

P.PID ORACLE_PROCESS_ID

FROM V$SESSION S, V$PROCESS P

WHERE S.PADDR = P.ADDR

--先找出OS PID

oradebug setospid 9999;

--set os PID

oradebug unlimit;

-- 设置Trace文件大小

oradebug event 10046 trace name context forever ,level 12;

-- 开启级别为12的Trace

Oradebug event 10046 trace name context off;

--关闭trace

/*使用DBMS_SYSTEM.SET_EV包, 也可以进行基于SID,SERIAL的跟踪*/

EXEC SYS.DBMS_SYSTEM.SET_EV(:sid, :serial, 10046, 12, '');

-- 开启level 12的Trace

EXEC SYS.DBMS_SYSTEM.SET_EV(:sid, :serial, 10046, 0, '');

-- 关闭Trace

/*DBMS_SUPPORT包默认情况下并没有包含在数据库中，需要通过运行$ORACLE_HOME/rdbms/admin/dbmssupp.sql 安装之后才能使用。*/

--开启自身进程：

EXEC SYS.DBMS_SUPPORT.START_TRACE(true, true);

EXEC SYS.DBMS_SUPPORT.STOP_TRACE();

--开启其他的进程

EXEC SYS.DBMS_SUPPORT.START_TRACE_IN_SESSION(:sid, :serial, true, true);

EXEC SYS.DBMS_SUPPORT.STOP_TRACE_IN_SESSION(:sid, :serial);

/*******************************使用DBMS_MONITOR包************************************/

--当前

EXEC DBMS_MONITOR.SESSION_TRACE_ENABLE(WAITS=>true,BINDS=>true);

EXEC DBMS_MONITOR.SESSION_TRACE_DISABLE();

--其他的进程

EXEC DBMS_MONITOR.SESSION_TRACE_ENABLE(:sid, :serial, true, true);

EXEC DBMS_MONITOR.SESSION_TRACE_DISABLE(:sid, :serial);

--依靠client_identifier来trace

EXECUTE DBMS_MONITOR.CLIENT_ID_TRACE_ENABLE('client_name', true, true);

EXECUTE DBMS_MONITOR.CLIENT_ID_TRACE_DISABLE('client_name');

/*************************************数据库级的trace**********************************/

EXEC DBMS_MONITOR.DATABASE_TRACE_ENABLE(true, true);

EXEC DBMS_MONITOR.DATABASE_TRACE_DISABLE();