I did. In fact without that step, rhq-installer.bat in test mode (-t) used to fail.

After installing the driver, the rhq-installer.bat in test mode passes as can be seen below:

(Also I can see a ojdbc14.jar.index created in the same folder that I copied the ojdbc14.jar oracle driver into [<RHQinstall dir>\modules\org\rhq\oracle\main])

C:\_management\rhq-server-4.6.0\bin>rhq-installer.bat -t

Starting RHQ Server installer ...

11:22:29,359 INFO  [org.jboss.modules] JBoss Modules version 1.1.1.GA

11:22:29,468 INFO  [org.rhq.enterprise.server.installer.Installer] Starting inst

aller...

11:22:29,484 INFO  [org.rhq.enterprise.server.installer.InstallerServiceImpl] Th

e server is preconfigured and ready for auto-install.

11:22:29,593 INFO  [org.xnio] XNIO Version 3.0.3.GA

11:22:29,609 INFO  [org.xnio.nio] XNIO NIO Implementation Version 3.0.3.GA

11:22:29,625 INFO  [org.jboss.remoting] JBoss Remoting version 3.2.3.GA

11:22:35,656 INFO  [org.rhq.enterprise.server.installer.InstallerServiceImpl] In

stalling into app server version [7.1.1.Final]

11:22:36,421 INFO  [org.rhq.enterprise.server.installer.ServerInstallUtil] Datab

ase is supported: oracle10(oracle:10)

11:22:38,687 INFO  [org.rhq.enterprise.server.installer.InstallerServiceImpl] Th

is [[name=DDT3TM81, address=127.0.0.1, port=7080, secureport=7443]] will be cons

idered a reinstallation of an existing server [[name=DDT3TM81, address=127.0.0.1

, port=7080, secureport=7443]]

11:22:38,765 INFO  [org.rhq.enterprise.server.installer.InstallerServiceImpl] Th

e app server where the installation will go is found at: C:\_management\rhq-serv

er-4.6.0\jbossas

11:22:38,765 INFO  [org.rhq.enterprise.server.installer.InstallerServiceImpl] It

looks like everything is OK and you can start the installation.

but when I run the installer without the -t option, I get the error in the original post.

Is it possible that RHQ 4.6.0 is shipping with a buggy version of JBoss (7.1.1 Final as seen from the log above)

(Reason: When I searched for the error, I found a known issue https://issues.jboss.org/browse/AS7-5616

in JBOSS 7 which seems to be fixed in 7.1.4 Final)

Additional information from rhq-installer.log:

19:27:29,671 INFO  [org.rhq.enterprise.server.installer.ServerInstallUtil] Oracle JDBC driver is already deployed

19:27:29,687 INFO  [org.rhq.enterprise.server.installer.ServerInstallUtil] Postgres JDBC driver is already deployed

19:27:29,765 WARN  [org.rhq.enterprise.server.installer.InstallerServiceImpl] deployServices failed: org.rhq.common.jbossas.client.controller.FailureException: Failed to create Oracle datasources: {"JBAS014653: Composite operation failed and was rolled back. Steps that failed:" => {"Operation step-1" => {"JBAS014653: Composite operation failed and was rolled back. Steps that failed:" => {"Operation step-1" => "JBAS010468: Driver named \"oracle\" is not installed."}},"Operation step-2" => "JBAS014654: Composite operation was rolled back"}}

          at org.rhq.enterprise.server.installer.ServerInstallUtil.createNewDatasources_Oracle(ServerInstallUtil.java:620) [rhq-installer-util-4.6.0.jar:4.6.0]

          at org.rhq.enterprise.server.installer.ServerInstallUtil.createNewDatasources(ServerInstallUtil.java:522) [rhq-installer-util-4.6.0.jar:4.6.0]

          at org.rhq.enterprise.server.installer.InstallerServiceImpl.deployServices(InstallerServiceImpl.java:1100) [rhq-installer-util-4.6.0.jar:4.6.0]

          at org.rhq.enterprise.server.installer.InstallerServiceImpl.install(InstallerServiceImpl.java:291) [rhq-installer-util-4.6.0.jar:4.6.0]

          at org.rhq.enterprise.server.installer.Installer.doInstall(Installer.java:130) [rhq-installer-util-4.6.0.jar:4.6.0]

          at org.rhq.enterprise.server.installer.Installer.main(Installer.java:57) [rhq-installer-util-4.6.0.jar:4.6.0]

          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.6.0_33]

          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [rt.jar:1.6.0_33]

          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [rt.jar:1.6.0_33]

          at java.lang.reflect.Method.invoke(Method.java:597) [rt.jar:1.6.0_33]

          at org.jboss.modules.Module.run(Module.java:260)

          at org.jboss.modules.Main.main(Main.java:291)