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