oracle 查看隐藏参数

原文链接
隐藏参数 (hidden parameters) ，由oracle内部使用，以 ‘_’ 开头。

可以通过以下两种方式查看所有隐藏参数：

[sql] view plain copy
SELECT   i.ksppinm name,
           i.ksppdesc description,
           CV.ksppstvl VALUE,
           CV.ksppstdf isdefault,
           DECODE (BITAND (CV.ksppstvf, 7),
                   1, 'MODIFIED',
                   4, 'SYSTEM_MOD',
                   'FALSE')
              ismodified,
           DECODE (BITAND (CV.ksppstvf, 2), 2, 'TRUE', 'FALSE') isadjusted
    FROM   sys.x$ksppi i, sys.x$ksppcv CV
   WHERE       i.inst_id = USERENV ('Instance')
           AND CV.inst_id = USERENV ('Instance')
           AND i.indx = CV.indx
           AND i.ksppinm LIKE '/_%' ESCAPE '/'
ORDER BY   REPLACE (i.ksppinm, '_', '');  

[sql] view plain copy
SELECT   ksppinm, ksppstvl, ksppdesc
  FROM   x$ksppi x, x$ksppcv y
 WHERE   x.indx = y.indx AND TRANSLATE (ksppinm, '_', '#') LIKE '#%';  

示例：如果想查看_db_block_hash_buckets的参数值

[sql] view plain copy
SELECT   ksppinm, ksppstvl, ksppdesc
  FROM   x$ksppi x, x$ksppcv y
 WHERE   x.indx = y.indx AND  ksppinm = '_db_block_hash_buckets';