db4o

ObjectServer.openClient Method 

opens a client against this server.

ObjectContainer openClient();

Remarks

opens a client against this server.

A client opened with this method operates within the same VM as the server. Since an embedded client can use direct communication, without an in-between socket connection, performance will be better than a client opened with openClient

Every client has it's own transaction and uses it's own cache for it's own version of all peristent objects.

See Also

ObjectServer Interface | com.db4o Namespace