What's the command to find out patch version?

[gandolf989]

You can try this in 8i:

FUNCTION DbReleaseNumber RETURN VARCHAR2 IS
VersionNumber VARCHAR2(20);
Compatibility VARCHAR2(20);
BEGIN
DBMS_UTILITY.Db_Version( VersionNumber, Compatibility);
RETURN VersionNumber;
EXCEPTION
WHEN OTHERS THEN
return(NULL);
END;