oracle patch applied detail

The easiest way to get this information is from the OPatch utility.  The OPatch utility can be found under $ORACLE_HOME/OPatch.

Example:

$ORACLE_HOME/OPatch/opatch lsinventory

The above command will list out all the currently applied patches to your Oracle environment using the files in the oraInventory. Today i did some googling to find out  same information from inside the database, there are a two views that can be used.

Example:

SQL>select * from sys.v$version ;

SQL>select * from sys.registry$history;

I really like the sys.registry$history because if gives you a running history of your applied patches and upgrades.