让Oracle的 SHOW PARAMETER 命令显示隐藏参数
转自 http://blog.csdn.net/staricqxyz/article/details/8624549
Find internal of "show parameter" by session tracing
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
SQL> alter session set sql_trace=true;
Session altered.
SQL> oradebug setmypid
Statement processed.
SQL> show parameter optimizer
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
optimizer_capture_sql_plan_baselines boolean FALSE
optimizer_dynamic_sampling integer 2
optimizer_features_enable string 11.2.0.3
optimizer_index_caching integer 0
optimizer_index_cost_adj integer 100
optimizer_mode string ALL_ROWS
optimizer_secure_view_merging boolean TRUE
optimizer_use_invisible_indexes boolean FALSE
optimizer_use_pending_statistics boolean FALSE
optimizer_use_sql_plan_baselines boolean TRUE
SQL> oradebug tracefile_name
/u01/app/oracle/diag/rdbms/zhongwc/zhongwc/trace/zhongwc_ora_32320.trc
Find internal sql statement in trace file.The major statement in trace file looks like following.It's clear that "show parameter" actually make query on view v$parameter.
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_CL_PLUS_SHOW_PARAM
FROM V$PARAMETER
WHERE UPPER(NAME) LIKE UPPER('%optimizer%')
ORDER BY NAME_COL_PLUS_SHOW_PARAM, ROWNUM;
Examing definition of view v$parameter
SQL> SELECT view_definition FROM v$fixed_view_definition WHERE view_name = 'V$PARAMETER';
VIEW_DEFINITION
----------------------------------------------------------------------------------------------------
select NUM , NAME , TYPE , VALUE , DISPLAY_VALUE, ISDEFAULT , ISSES_MODIFIABLE , ISSYS_MODIFIABLE ,
ISINSTANCE_MODIFIABLE, ISMODIFIED , ISADJUSTED , ISDEPRECATED, ISBASIC, DESCRIPTION, UPDATE_COMMENT
, HASH from GV$PARAMETER where inst_id = USERENV('Instance')
Examing definition of view gv$parameter,hidden init parameters start with character '_'
SQL> SELECT view_definition FROM v$fixed_view_definition WHERE view_name = 'GV$PARAMETER';
VIEW_DEFINITION
--------------------------------------------------------------------------------
select x.inst_id,x.indx+1,ksppinm,ksppity,ksppstvl, ksppstdvl, ksppstdf, decode
(bitand(ksppiflg/256,1),1,'TRUE','FALSE'), decode(bitand(ksppiflg/65536,3),1,'I
MMEDIATE',2,'DEFERRED', 3,'IMMEDIATE','FALSE'),
decode(bitand(ksppiflg,4),4,'FALSE', decod
e(bitand(ksppiflg/65536,3), 0, 'FALSE', 'TRUE')), decode(bitand(ksppstvf,7),
1,'MODIFIED',4,'SYSTEM_MOD','FALSE'), decode(bitand(ksppstvf,2),2,'TRUE','FALSE
'), decode(bitand(ksppilrmflg/64, 1), 1, 'TRUE', 'FALSE'), decode(bitand(ksppi
lrmflg/268435456, 1), 1, 'TRUE', 'FALSE'), ksppdesc, ksppstcmnt, ksppihash fro
m x$ksppi x, x$ksppcv y where (x.indx = y.indx) and bitand(ksppiflg,268435456)
= 0 and ((translate(ksppinm,'_','#') not like '##%') and ((translate(ksppinm
,'_','#') not like '#%') or (ksppstdf = 'FALSE') or (bitand(ksppstvf,5
) > 0)))
Create pseudo-view of v$paramter
[oracle@zhongwc ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Fri Mar 1 09:01:58 2013
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options
SQL> create or replace view my_v$parameter_with_hidden
(NUM,NAME , TYPE, display_Value , ISDEFAULT , ISSES_MODIFIABLE ,
ISSYS_MODIFIABLE ,ISMODIFIED , ISADJUSTED, DESCRIPTION,
UPDATE_COMMENT)
as
select x.indx+1,ksppinm,ksppity,ksppstvl,ksppstdf,
decode(bitand(ksppiflg/256,1),1,'TRUE','FALSE'),
decode(bitand(ksppiflg/65536,3),1,'IMMEDIATE',2,'DEFERRED',
3,'IMMEDIATE','FALSE'), decode(bitand(ksppstvf,7),
1,'MODIFIED',4,'SYSTEM_MOD','FALSE'),
decode(bitand(ksppstvf,2),2,'TRUE','FALSE'),
ksppdesc, ksppstcmnt
from x$ksppi x, x$ksppcv y
where (x.indx = y.indx)
/
View created.
SQL> grant select on my_v$parameter_with_hidden to system;
Grant succeeded.
SQL> conn system
Enter password:
Connected.
SQL> create synonym v$parameter for sys.my_v$parameter_with_hidden;
Synonym created.
able to use "show parameter" to show hidden init parameters
SQL> show parameter optimizer
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
_db_file_optimizer_read_count integer 8
_optimizer_adaptive_cursor_sharing boolean TRUE
_optimizer_adjust_for_nulls boolean TRUE
_optimizer_autostats_job boolean TRUE
_optimizer_aw_join_push_enabled boolean TRUE
_optimizer_aw_stats_enabled boolean TRUE
_optimizer_better_inlist_costing string ALL
_optimizer_block_size integer 8192
_optimizer_cache_stats boolean FALSE
_optimizer_cartesian_enabled boolean TRUE
_optimizer_cbqt_factor integer 50
_optimizer_cbqt_no_size_restriction boolean TRUE
_optimizer_ceil_cost boolean TRUE
_optimizer_coalesce_subqueries boolean TRUE
_optimizer_complex_pred_selectivity boolean TRUE
_optimizer_compute_index_stats boolean TRUE
_optimizer_connect_by_cb_whr_only boolean FALSE
_optimizer_connect_by_combine_sw boolean TRUE
_optimizer_connect_by_cost_based boolean TRUE
_optimizer_connect_by_elim_dups boolean TRUE
_optimizer_correct_sq_selectivity boolean TRUE
_optimizer_cost_based_transformation string LINEAR
