Oracle transaction Rollback doesn't work - vb.net

Question

I created an Oracle transaction trying to save some data in two tables and I caused an error at the second procedure to call the rollback and check if it works.
The first procedure creates a job in USER_SCHEDULER_JOBS using the sys.dbms_scheduler.create_job.
Private Function CreateJobDef() As Integer
Try
Cursor.Current = Cursors.WaitCursor
conn = New OracleConnection
conn.ConnectionString = gApp.ConnectString
conn.Open()
Dim cmd As OracleCommand = conn.CreateCommand()
Dim oraclTrans As OracleTransaction
oraclTrans = conn.BeginTransaction()
cmd.Transaction = oraclTrans
Try
cmd.CommandText = "TEST.CREATE_JOB_SCHEDULE"
cmd.CommandType = CommandType.StoredProcedure
cmd.Parameters.Clear()
OracleCommandBuilder.DeriveParameters(cmd)
cmd.Parameters("in_job_name").Value = txtName.Text
cmd.Parameters("in_schedule_name").Value = cboSchedule.SelectedValue
cmd.Parameters("in_enabled").Value = If(chkEnabled.Checked, 1, 0)
cmd.Parameters("in_comments").Value = txtComments.Text
cmd.ExecuteNonQuery()
'Everything is OK
'-----------------------------------------------
cmd.CommandText = "TEST.Update_Job_Def"
cmd.CommandType = CommandType.StoredProcedure
cmd.Parameters.Clear()
OracleCommandBuilder.DeriveParameters(cmd)
cmd.Parameters("in_job_id").Value = "WQwqwq" 'I set this to a string to cause an error in the second procedure to check the rollback
cmd.Parameters("in_job_name").Value = txtName.Text
cmd.Parameters("in_job_type").Value = cboType.SelectedItem
cmd.Parameters("in_report_nav_id").Value = cboReport.SelectedValue
cmd.Parameters("in_mail_address_to").Value = txtMailTo.Text
cmd.ExecuteNonQuery()
oraclTrans.Commit()
Catch ex As OracleException
Msgbox(ex.ToString)
oraclTrans.Rollback()
Catch ex As Exception
Msgbox(ex.ToString)
oraclTrans.Rollback()
Finally
conn.Close()
If conn IsNot Nothing Then conn.Dispose()
If cmd IsNot Nothing Then cmd.Dispose()
End Try
Catch ex As OracleException
Msgbox(ex.ToString)
Catch ex As Exception
Msgbox(ex.ToString)
Finally
Cursor.Current = Cursors.Default
End Try
End Function
The problem is that the first procedure is create a new Job, although I have caused an error at the second procedure and the rollback is called.
Any ideas?
Thanks

Answer 1

There is an implicit commit in a DDL statement and in many Oracle procedure calls that create or modify objects such as a scheduled job. Therefore you cannot rollback a job creation procedure.