Hidden Initialization Parameters
Norbert Debes · Apress eBooks · 2009
The view V$PARAMETER provides access to documented initialization parameters. This view is built on top of the X$ fixed tables X$KSPPI and X$KSPPCV (more on X$ fixed tables in Part IV). All hidden parameters start with one or two underscores. V$PARAMETER is built in such a way that it lists documented parameters only. There are 540 undocumented parameters in Oracle9i Release 2, 1,124 in Oracle10g Release 2, and 1,627 in Oracle11g. Their names and a short description may be retrieved with the following query (file hidden_parameters.sql): $$ \begin{gathered} SQL > SELECT ksppinm name, \hfill \\ ksppstvl value, \hfill \\ ksppdesc description \hfill \\ FROM x\$ ksppi x, x\$ ksppcv y \hfill \\ WHERE (x.indx = y.indx) \hfill \\ AND x.inst\_id = userenv('instance') \hfill \\ AND x.inst\_id = y.inst\_id \hfill \\ AND ksppinm LIKE '\backslash \_\% ' ESCAPE '\backslash ' \hfill \\ ORDER by name; \hfill \\ \end{gathered} $$