title: ORA-08177: can't serialize access for this transaction
body: <p>I have a very simple code using ADO.NET which throws ORA-08177 exception. I am not sure what's wrong with this. I am trying this on a windows vista machine which has oracle 32 bit client installed. My compile option for visual studio is set to x86 platform.</p>
  
  <pre><code>Dim connection As OracleConnection = Nothing
  Dim transaction As OracleTransaction = Nothing
  
  Try
      connection = New OracleConnection("Data Source=ora10;User Id=userid;Password=passwd;")
      connection.Open()
  
      transaction = connection.BeginTransaction(IsolationLevel.Serializable)
  
      Dim inputStream As New System.IO.FileStream("Dummy.xls", IO.FileMode.Open)
      Dim fileLength As Integer = CType(inputStream.Length, Integer)
      Dim input(fileLength) As Byte
  
      Try
          inputStream.Read(input, 0, fileLength)
      Finally
          If inputStream IsNot Nothing Then inputStream.Close()
      End Try
  
      Dim deleteSql As String = "DELETE FROM TABLE1 WHERE Version = 'v1' "
  
      Dim cmd As New OracleCommand(deleteSql, connection, transaction)
      cmd.ExecuteNonQuery()
  
      Dim insertQuery As String = "INSERT INTO TABLE1 (VERSION, DATA) VALUES (:VERSION, :DATA) "
      Dim insertCmd As OracleCommand = New OracleCommand(insertQuery, connection, transaction)
      insertCmd.Parameters.Clear()
      insertCmd.CommandType = Data.CommandType.Text
      insertCmd.Parameters.AddWithValue(":VERSION", "v1")
      insertCmd.Parameters.AddWithValue(":DATA", input)
  
      insertCmd.ExecuteNonQuery()
      transaction.Commit()
  
  Catch
      If transaction IsNot Nothing Then transaction.Rollback()
      Throw
  Finally
      If transaction IsNot Nothing Then transaction.Dispose()
      If connection IsNot Nothing AndAlso connection.State &lt;&gt; ConnectionState.Closed Then connection.Close()
  End Try
  </code></pre>
  
  <p>Important thing to note: (I am not sure if they are connected) but I do not face this problem if I uninstall latest windows updates from my machine.</p>
  
  <p>Has anyone faced this or have any clue about what is going on here?</p>
  
  <p>Edit:-</p>
  
  <p>I have some progress where I have found out that this problem occurs only when we have blob column type in question. for simple columns it works fine.</p>
  
  <p>Other details (not sure if that makes a difference)</p>
  
  <p>I am working on 64 bit windows vista business machine. 
  I have installed 32 bit oracle client for windows vista (since 64 bit oracle client does not work on vista).
  I am compiling my project for a x86 (32 bit environment) in visual studio.
  And this is a console application and I know that nobody else is hitting the database at this time. so there cannot be multiple transactions.</p>
  
  <p>And I do not see this problem if I uninstall latest windows update. (KB963027, KB967190, KB959426, KB960225, KB960803, KB952004, KB956572, KB958687, KB958690, KB958481, KB958483, KB943729)</p>