实验：查看隐藏参数
1.查看隐藏参数脚本：
set linesize 120
col name for a45 trunc
col value for a20
col pdesc for a50 trunc
SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.KSPPDESC PDESC
FROM SYS.x$ksppi x, SYS.x$ksppcv y
WHERE x.indx = y.indx AND x.ksppinm LIKE '%&par%';
举例：查看shared隐藏参数
SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.KSPPDESC PDESC
2 FROM SYS.x$ksppi x, SYS.x$ksppcv y
3 WHERE x.indx = y.indx AND x.ksppinm LIKE '%&par%';
Enter value for par: shared
old 3: WHERE x.indx = y.indx AND x.ksppinm LIKE '%&par%'
new 3: WHERE x.indx = y.indx AND x.ksppinm LIKE '%shared%'
NAME VALUE PDESC
--------------------------------------------- -------------------- --------------------------------------------------
shared_memory_address 0 SGA starting address (low order 32-bits on 64-bit
hi_shared_memory_address 0 SGA starting address (high order 32-bits on 64-bit
__shared_pool_size 62914560 Actual size in bytes of shared pool
shared_pool_size 0 size in bytes of shared pool
shared_pool_reserved_size 3145728 size in bytes of reserved area of shared pool
_shared_pool_reserved_pct 5 percentage memory of the shared pool allocated for
_shared_pool_reserved_min_alloc 4400 minimum allocation size in bytes for reserved area
_io_shared_pool_size 4194304 Size of I/O buffer pool from SGA
_shared_pool_max_size 0 shared pool maximum size when auto SGA enabled
shared_servers 1 number of shared servers to start up
max_shared_servers max number of shared servers
NAME VALUE PDESC
--------------------------------------------- -------------------- --------------------------------------------------
shared_server_sessions max number of shared server sessions
_all_shared_dblinks treat all dblinks as shared
_dm_max_shared_pool_pct 1 max percentage of the shared pool to use for a min
2.查看ORACLE有多少参数
SQL> select count(*) from x$ksppi;
COUNT(*)
----------
1385
