Intento hacer una conexión desde Pentaho a una base de Oracle

Estoy intentando hacer una conexión desde Pentaho hacia una base de Oracle pero me marca el siguiente error

org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database

Driver class 'oracle. Rdb. Jdbc. RdbThin. Driver' could not be found, make sure the 'Oracle RDB' driver (jar file) is installed.
Oracle. Rdb. Jdbc. RdbThin. Driver

At org. Pentaho. Di. Core.database.Database.normalConnect(Database.java:497)
At org. Pentaho. Di. Core.database.Database.connect(Database.java:389)
At org. Pentaho. Di. Core.database.Database.connect(Database.java:360)
At org. Pentaho. Di. Core.database.Database.connect(Database.java:350)
At org. Pentaho. Di. Core.database.DatabaseFactory.getConnectionTestReport(DatabaseFactory.java:85)
At org. Pentaho. Di. Core.database.DatabaseFactory.getConnectionTestResults(DatabaseFactory.java:115)
At org. Pentaho. Di. Core.database.DatabaseMeta.testConnectionSuccess(DatabaseMeta.java:2859)
At org. Pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:659)
At sun. Reflect. NativeMethodAccessorImpl. Invoke0(Native Method)
At sun. Reflect. NativeMethodAccessorImpl. Invoke(Unknown Source)
At sun. Reflect. DelegatingMethodAccessorImpl. Invoke(Unknown Source)
At java. Lang. Reflect. Method. Invoke(Unknown Source)
At org. Pentaho. Ui. Xul. Impl. AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:313)
At org. Pentaho. Ui. Xul. Impl. AbstractXulComponent.invoke(AbstractXulComponent.java:157)
At org. Pentaho. Ui. Xul. Impl. AbstractXulComponent.invoke(AbstractXulComponent.java:141)
At org. Pentaho. Ui. Xul. Swt. Tags. SwtButton.access$500(SwtButton.java:43)
At org. Pentaho. Ui. Xul. Swt. Tags.SwtButton$4.widgetSelected(SwtButton.java:137)
At org. Eclipse. Swt. Widgets. TypedListener.handleEvent(TypedListener.java:252)
At org. Eclipse. Swt. Widgets. EventTable.sendEvent(EventTable.java:89)
At org. Eclipse. Swt. Widgets. Display.sendEvent(Display.java:4209)
At org. Eclipse. Swt. Widgets. Widget.sendEvent(Widget.java:1037)
At org. Eclipse. Swt. Widgets. Display.runDeferredEvents(Display.java:4026)
At org. Eclipse. Swt. Widgets. Display.readAndDispatch(Display.java:3626)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:823)
at org.eclipse.jface.window.Window.open(Window.java:799)
At org. Pentaho. Di. Ui. Xul. KettleDialog.show(KettleDialog.java:89)
At org. Pentaho. Di. Ui. Xul. KettleDialog.show(KettleDialog.java:56)
At org. Pentaho. Di. Ui. Core.database.dialog.XulDatabaseDialog.open(XulDatabaseDialog.java:124)
At org. Pentaho. Di. Ui. Core.database.dialog.DatabaseDialog.open(DatabaseDialog.java:61)
At org. Pentaho. Di. Ui. Spoon. Delegates. SpoonDBDelegate.newConnection(SpoonDBDelegate.java:495)
At org. Pentaho. Di. Ui. Spoon. Delegates. SpoonDBDelegate.newConnection(SpoonDBDelegate.java:482)
At org. Pentaho. Di. Ui. Spoon. Spoon.newConnection(Spoon.java:8893)
At sun. Reflect. NativeMethodAccessorImpl. Invoke0(Native Method)
At sun. Reflect. NativeMethodAccessorImpl. Invoke(Unknown Source)
At sun. Reflect. DelegatingMethodAccessorImpl. Invoke(Unknown Source)
At java. Lang. Reflect. Method. Invoke(Unknown Source)
At org. Pentaho. Ui. Xul. Impl. AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:313)
At org. Pentaho. Ui. Xul. Impl. AbstractXulComponent.invoke(AbstractXulComponent.java:157)
At org. Pentaho. Ui. Xul. Impl. AbstractXulComponent.invoke(AbstractXulComponent.java:141)
At org. Pentaho. Ui. Xul. Jface. Tags. JfaceMenuitem.access$100(JfaceMenuitem.java:44)
At org. Pentaho. Ui. Xul. Jface. Tags.JfaceMenuitem$1.run(JfaceMenuitem.java:107)
At org. Eclipse. Jface. Action. Action.runWithEvent(Action.java:474)
At org. Eclipse. Jface. Action. ActionContributionItem. HandleWidgetSelection(ActionContributionItem.java:580)
At org. Eclipse. Jface. Action. ActionContributionItem.lambda$4(ActionContributionItem.java:414)
At org. Eclipse. Swt. Widgets. EventTable.sendEvent(EventTable.java:89)
At org. Eclipse. Swt. Widgets. Display.sendEvent(Display.java:4209)
At org. Eclipse. Swt. Widgets. Widget.sendEvent(Widget.java:1037)
At org. Eclipse. Swt. Widgets. Display.runDeferredEvents(Display.java:4026)
At org. Eclipse. Swt. Widgets. Display.readAndDispatch(Display.java:3626)
At org. Pentaho. Di. Ui. Spoon. Spoon.readAndDispatch(Spoon.java:1421)
At org. Pentaho. Di. Ui. Spoon. Spoon.waitForDispose(Spoon.java:8006)
At org. Pentaho. Di. Ui. Spoon. Spoon.start(Spoon.java:9388)
At org. Pentaho. Di. Ui. Spoon. Spoon.main(Spoon.java:711)
At sun. Reflect. NativeMethodAccessorImpl. Invoke0(Native Method)
At sun. Reflect. NativeMethodAccessorImpl. Invoke(Unknown Source)
At sun. Reflect. DelegatingMethodAccessorImpl. Invoke(Unknown Source)
At java. Lang. Reflect. Method. Invoke(Unknown Source)
At org. Pentaho.commons.launcher.Launcher.main(Launcher.java:92)
Caused by: org.pentaho.di.core.exception.KettleDatabaseException:
Driver class 'oracle. Rdb. Jdbc. RdbThin. Driver' could not be found, make sure the 'Oracle RDB' driver (jar file) is installed.
Oracle. Rdb. Jdbc. RdbThin. Driver

At org. Pentaho. Di. Core.database.Database.connectUsingClass(Database.java:537)
At org. Pentaho. Di. Core.database.Database.normalConnect(Database.java:481)
... 57 more
Caused by: java. Lang. ClassNotFoundException: oracle. Rdb. Jdbc. RdbThin. Driver
At java.net.URLClassLoader.findClass(Unknown Source)
At java. Lang. ClassLoader. LoadClass(Unknown Source)
At java. Lang. ClassLoader. LoadClass(Unknown Source)
At org. Pentaho. Di. Core.database.Database.connectUsingClass(Database.java:515)
... 58 more