Configuring Exclusive Read Connections

An exclusive connection is one that TopLink allocates specifically to a given session and one that is never used by any other session.

By default, TopLink acquires read connections for a client session from a shared read connection pool. In this case, different sessions may reuse connections and may use connections concurrently.

Allowing concurrent reads on the same connection reduces the number of read connections required and reduces the risk of having to wait for an available connection. However, many JDBC drivers do not support concurrent reads.

If you are using internal connection pools (see "Internal Connection Pools"), you can configure TopLink to acquire an exclusive connection from the read connection pool.

If you are using external connection pools, read connections are always exclusive.

Using TopLink Workbench

To configure a TopLink read connection pool to allocate exclusive connections, use this procedure:

1. Expand a server session to reveal its connection pools in the Navigator.

2. Select a read connection pool in the Navigator. Its properties appear in the Editor.

3. Click the Login tab. The Login tab appears.

4. Click the Connection subtab. The Connection subtab appears.

   Figure 89-6 Login Tab, Connection Subtab, Exclusive Connections Option

   
   Description of "Figure 89-6 Login Tab, Connection Subtab, Exclusive Connections Option"
   
   

Select the Exclusive Connections option to configure TopLink to acquire an exclusive connection from the read connection pool.

Deselect the Exclusive Connections option to configure TopLink to share read connections and allow concurrent reads. Before selecting this option, ensure that your JDBC driver supports concurrent reads.