oracle 查看隐含参数

v$parameter视图中查询参数的时候其实都是通过x$ksppi和x$ksppcv这两个内部视图中得到的。

可以通过如下方式查询当前实例的所有隐含参数:

  select

  x.ksppinm name,

  y.ksppstvl value,

  y.ksppstdf isdefault,

  decode(bitand(y.ksppstvf,7),1,'MODIFIED',4,'SYSTEM_MOD','FALSE') ismod,

  decode(bitand(y.ksppstvf,2),2,'TRUE','FALSE') isadj

  from

  sys.x$ksppi x,

  sys.x$ksppcv y

  where

  x.inst_id = userenv('Instance') and

  y.inst_id = userenv('Instance') and

  x.indx = y.indx

  order by

  translate(x.ksppinm, ' _', ' ')

  /

修改隐含参数的方法:alter system set "_cursor_bind_capture_interval"=5 (记得加引号)

-----下面部分给出了如何知道隐含参数查询的方法-------

我们在查看内存参数时会看到如下执行计划:

SQL> set autotrace traceonly
SQL> select * from v$parameter;

342 rows selected.


Execution Plan
----------------------------------------------------------
Plan hash value: 1128103955

------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 4414 | 1 (100)| 00:00:01 |
|* 1 | HASH JOIN | | 1 | 4414 | 1 (100)| 00:00:01 |
|* 2 | FIXED TABLE FULL| X$KSPPI | 1 | 249 | 0 (0)| 00:00:01 |
| 3 | FIXED TABLE FULL| X$KSPPCV | 100 | 406K| 0 (0)| 00:00:01 |
------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

1 - access("X"."INDX"="Y"."INDX")
filter(TRANSLATE("KSPPINM",'_','#') NOT LIKE '#%' OR
"KSPPSTDF"='FALSE' OR BITAND("KSPPSTVF",5)>0)
2 - filter("X"."INST_ID"=USERENV('INSTANCE') AND
BITAND("KSPPIFLG",268435456)=0 AND TRANSLATE("KSPPINM",'_','#') NOT
LIKE '##%')


Statistics
----------------------------------------------------------
64 recursive calls
0 db block gets
6 consistent gets
0 physical reads
0 redo size
35905 bytes sent via SQL*Net to client
661 bytes received via SQL*Net from client
24 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
342 rows processed

SQL> desc x$ksppi;
Name Null? Type
----------------------------------------------------- -------- ------------------------------------
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KSPPINM VARCHAR2(80)
KSPPITY NUMBER
KSPPDESC VARCHAR2(255)
KSPPIFLG NUMBER
KSPPILRMFLG NUMBER
KSPPIHASH NUMBER

SQL> desc x$ksppcv
Name Null? Type
----------------------------------------------------- -------- ------------------------------------
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KSPPSTVL VARCHAR2(4000)
KSPPSTDVL VARCHAR2(4000)
KSPPSTDF VARCHAR2(9)
KSPPSTVF NUMBER
KSPPSTCMNT VARCHAR2(255)

由此可见,可以通过下面方法查询所有隐含参数

  select

  x.ksppinm name,

  y.ksppstvl value,

  y.ksppstdf isdefault,

  decode(bitand(y.ksppstvf,7),1,'MODIFIED',4,'SYSTEM_MOD','FALSE') ismod,

  decode(bitand(y.ksppstvf,2),2,'TRUE','FALSE') isadj

  from

  sys.x$ksppi x,

  sys.x$ksppcv y

  where

  x.inst_id = userenv('Instance') and

  y.inst_id = userenv('Instance') and

  x.indx = y.indx

  order by

  translate(x.ksppinm, ' _', ' ')

  /


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