Patch utility interface
This is also undocumented feature.As name suggest this utility is used to install patches or to be more precise online patches without shooting down instance ( as you know Oracle now offers online patching ).
This patch utility can be invoked by running oradebug command:
Here is list of all available options which are self descriptive:
[list|install|remove|disable|enable] <file> <temp>
temp = (disabled at restart
file = (in $ORACLE_HOME/hpatch/)
$ORACLE_HOME/hpatch directory contains shared libraries used by online patching.
$ORACLE_HOME/hpatch/orapatch@.cfg ( configuration file )
Oracle has dummy patch 6198642 which can be used to test online patching.You can see it on Laurent’s blog:
and more on online patching: