I have a simple test program which calls the Connection.setReadOnly(true) and then checks the readonly mode of that connection. In Network Server mode, the Connection.isReadOnly returns false even after Connection.setReadOnly(true). Same test program works fine when run in embedded mode, ie Connection.isReadOnly returns true after Connection.setReadOnly(true) is executed.
Following is the test code snippet
con = DriverManager.getConnection("jdbc:derby://localhost:1527/db7173;create=true", "APP", "APP");
System.out.println("Check default connection.isReadOnly " + con.isReadOnly());
System.out.println("After connection.setReadOnly(true), what is isReadOnly " + con.isReadOnly());
The output of this code in Network Server is as follows
Check default connection.isReadOnly? false
After connection.setReadOnly(true), what is isReadOnly? false
I looked at the Network Client code and found the problem to be in the Network Client.
org.apache.derby.client.am.Connection.setReadOnly method simply doesn't do anything with the supplied value, ie it doesn't pass any information to the Network Server for this call. In addition, it has following comment
// This is a hint to the driver only, so this request is silently ignored.
// PROTOCOL can only flow a set-read-only before the connection is established.
In the same class, isReadOnly always returns false. This explains the current behavior of Network Server. But are we really limited by the DRDA protocol here as the comments in setReadOnly seem to imply?
Anyone more familiar with DRDA specification and/or this code in Derby, can they share any information on DRDA spec and Derby behavior in this area?