Database Connections

You can access a database either with a direct connection from a data instance or a client/server connection over an external network.

• Direct connection: An application connects directly to a data instance of a database that they specify.

  An application using a direct connection runs on the same system as the database. A direct connection provides extremely fast performance as no inter-process communication (IPC) of any kind is required. However, if the specified data instance is down, the connection is not forwarded to another data instance and an error is returned.

• Client/server connection: An application using a client/server connection may run on a data instance or on any host with access to the external network. Client applications are automatically connected to a working data instance.

  All exchanges between client and server are sent over a TCP/IP connection. If the client and server reside on separate hosts in the internal network, they communicate by using sockets and TCP/IP.

  If a data instance fails, TimesTen Scaleout automatically re-connects to another working data instance. You can configure options to control this process, if necessary.

  Note:

  If desired, you can specify that a client/server connection connects to a specific data instance.

If your workload only requests data from the local element, then a direct connection is the best method for your application as this provides faster access than a client/server connection. However, if your workload entails that your application may need to switch between data instances for whichever data instance is readily available and retrieves data from the multiple elements, then a client/server connection may provide better throughput.