How many maximum connections can oracle have?

Oracle has two types of connection architecture:

• In dedicated server mode, each connection has a server process and you should have roughly the same limitations as in MySQL. This is the default connection mode and is recommended for small setup.
• In shared server mode the connections will share the server processes:

Shared server architecture eliminates the need for a dedicated server process for each connection. A dispatcher directs multiple incoming network session requests to a pool of shared server processes. An idle shared server process from a shared pool of server processes picks up a request from a common queue, which means a small number of shared servers can perform the same amount of processing as many dedicated servers. Also, because the amount of memory required for each user is relatively small, less memory and process management are required, and more users can be supported.

The jump from dedicated server to shared server architecture will be dictated by the number of connections and the workload. A mix of the two is possible (long running batch jobs in dedicated, front end web application in shared architecture).