Can I set the JDBC isolation level from a Tomcat Context?

Question

I have a web application running in Tomcat 6, and I\'ve managed to configure it to use the built-in DBCP connection pooling, and all is working very well, however I suspect

Answer 1

Yes, you can set that with defaultTransactionIsolation attribute in the Resource element.

<Context antiResourceLocking="false" privileged="true">
        <Resource 
            defaultTransactionIsolation="READ_UNCOMMITTED"
            name="jdbc/Connection" 
            auth="Container" 
            type="javax.sql.DataSource"
            maxActive="100" 
            maxIdle="30" 
            maxWait="10000"
            driverClassName="net.sourceforge.jtds.jdbc.Driver"
            url="jdbc:jtds:sqlserver://...etc..."
        />

From the docs:

defaultTransactionIsolation¨

TransactionIsolation state of connections created by this pool. One of the following: (see javadoc )

• NONE
• READ_COMMITTED
• READ_UNCOMMITTED
• REPEATABLE_READ
• SERIALIZABLE

Answer 2

I was looking for snapshot isolation level. The setting which was reported correctly by the database server was

defaultTransactionIsolation="4096"

You may confirm by a query to sys.dm_exec_sessions which should report transaction_isolation_level = 5. Hope it helps someone.