Enterprise tarball Corda distribution can only load JDBC jars from relative ./drivers directory.
The Capsule version can use directory specified by jarDirs config property and jarDirs was documented as a way to add JDBC drivers.
To make it consistent between tarball and Capsule version enterprise docs will be updated to use ./drivers dir, still preserving jarDirsbut state this option is not advisable and depending on the distribution may not work.