1、使用trace查找show parameter执行语句
alter session set events '10046 trace name context forever,level 12';
show parameter process;
alter session set events '10046 trace name context off';
2、查找trace文件
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
3、格式化trace文件
tkprof D:\oracle\diag\rdbms\xff\xff\trace\xff_ora_4780.trc D:\oracle\diag\rdbms\xff\xff\trace\abc.txt
4、找出对应sql语句
SELECT NAME NAME_COL_PLUS_SHOW_PARAM,
DECODE(TYPE,
1,
'boolean',
2,
'string',
3,
'integer',
4,
'file',
5,
'number',
6,
'big integer',
'unknown') TYPE,
DISPLAY_VALUE VALUE_COL_PLUS_SHOW_PARAM
FROM V$PARAMETER
WHERE UPPER(NAME) LIKE UPPER('%process%')
ORDER BY NAME_COL_PLUS_SHOW_PARAM, ROWNUM;
5、查找上面语句发现使用v$parameter对象
6、查看第一种来源
select owner,object_name,object_type from dba_objects where object_name ='V$PARAMETER';
select dbms_metadata.get_ddl(object_type=>'SYNONYM',NAME=>'V$PARAMETER',SCHEMA=>'PUBLIC') from dual;
7、无结果，查看第二种来源
select * from v$fixed_table where name ='V%PARAMETER%';
select * from v$fixed_view_definition where view_name='GV$PARAMETER';
8、得出结果，从中学习到数据库中的对象有两种来源
1)sys的fixed table : x$ksppi x, x$ksppcv y
2)sys的fixed view: GV$PARAMETER
3)sys的fixed view: V$PARAMETER
4) sys的普通view: V_$PARAMETER
5) public的synonym: v$parameter
所以，如果用sys访问v$parameter, 就是3=>2=>1
other user访问v$parameter, 就是5=>4=>3=>2=>1.
)
