1. /* 得到trace文件路径和名称 */

SELECT d.VALUE
 || '/'
 || LOWER (RTRIM (i.INSTANCE, CHR (0)))
 || '_ora_'
 || p.spid
 || '.trc' trace_file_name
 FROM (SELECT p.spid
 FROM v$mystat m, v$session s, v$process p
 WHERE m.statistic# = 1 AND s.SID = m.SID AND p.addr = s.paddr) p,
 (SELECT t.INSTANCE
 FROM v$thread t, v$parameter v
 WHERE v.NAME = 'thread'
 AND (v.VALUE = 0 OR t.thread# = TO_NUMBER (v.VALUE))) i,
 (SELECT VALUE
 FROM v$parameter
 WHERE NAME = 'user_dump_dest') d

2./* 显示产生锁定的sql语句 */

select /*+ NO_MERGE(a) NO_MERGE(b) NO_MERGE(c) */ a.username, a.machine, a.sid,a.serial#, a.last_call_et "Seconds", b.id1, c.sql_text "SQL" from v$session a, v$lock b,v$sqltext c where a.username is not null and a.lockwait = b.kaddr and c.hash_value =a.sql_hash_value;

3./* 查看oracle隐藏参数 */

select name,
 value,
 decode(isdefault, 'TRUE', 'Y', 'N') as "Default",
 decode(ISEM, 'TRUE', 'Y', 'N') as SesMod,
 decode(ISYM, 'IMMEDIATE', 'I', 'DEFERRED', 'D', 'FALSE', 'N') as SysMod,
 decode(IMOD, 'MODIFIED', 'U', 'SYS_MODIFIED', 'S', 'N') as Modified,
 decode(IADJ, 'TRUE', 'Y', 'N') as Adjusted,
 description
 from ( --GV$SYSTEM_PARAMETER 
 select x.inst_id as instance,
 x.indx + 1,
 ksppinm as name,
 ksppity,
 ksppstvl as value,
 ksppstdf as isdefault,
 decode(bitand(ksppiflg / 256, 1), 1, 'TRUE', 'FALSE') as ISEM,
 decode(bitand(ksppiflg / 65536, 3),
 1,
 'IMMEDIATE',
 2,
 'DEFERRED',
 'FALSE') as ISYM,
 decode(bitand(ksppstvf, 7), 1, 'MODIFIED', 'FALSE') as IMOD,
 decode(bitand(ksppstvf, 2), 2, 'TRUE', 'FALSE') as IADJ,
 ksppdesc as description
 from x$ksppi x, x$ksppsv y
 where x.indx = y.indx
 and substr(ksppinm, 1, 1) = '_'
 and x.inst_id = USERENV('Instance'))
 order by name;

4./* 根据系统中oracle的pid来查看sql */

select /*+ ORDERED */ sql_text from v$sqltext a where (a.hash_value,a.address) IN (select decode (sql_hash_value,0,prev_hash_value,sql_hash_value),decode (sql_hash_value,0,prev_sql_addr,sql_address) from v$session b where b.paddr =( select addr from v$process c where c.spid = '&pid')) order by piece ASC;