using same statement object to execute multiple queries in multiple threads?

Question

Is it a good idea to re-use java.sql.Statement object to execute multiple queries in multiple threads simultaneously?

I've read somewhere that it's recommended to reuse same statement object, however it was sequential execution.

Statement statement = con.createStatement();

Now if I use this single statement instance to run executeUpdate() for multiple queries in multiple threads simultaneously?

Note that it's not PreparedStatement and I am not getting any ResultSet.

I think answer depends on two scenarios:

1. If queries are mutually exclusive, then it should be okay.
2. If queries are working on same set of data, then there may be issues.

Is my understanding correct?

Thanks.

Answer 1

No, it's definitely not a good idea. For one, ResultSets are associated with a Statement. You don't want to be iterating through a ResultSet when another thread suddenly makes a new query (the ResultSet would be closed, at least if the driver is a well behaved one).

There is also nowhere an indication that Statements would be thread-safe. If it's not clearly indicated, it's not thread-safe (at least in most cases).