Also, maintaining record locks requires a persistent connection to the database server, which is not possible in disconnected applications.

In a client-server architecture, on the other hand, a persistent connection is typically used so that server state can be managed.

That persistent connection has psychological as well as practical effects.

By default, versions 6 and 7 use 2 persistent connections while version 8 uses 6.

They may not look like a web browser, but they're actually setting up persistent connections back to a server in order to communicate.

Each chat connection from client to server is a persistent connection.

So there you don't even need a persistent connection.

Now browsers are maintaining those persistent connections to web servers.

And so now there's a persistent connection.

It has a persistent connection to the DB to allow improved response speed.