What (if any) internal processes create connections with large connection numbers?

[Breck_Carter]

Alas, I didn't save the sa_conn_info() output, but I recently saw several consecutive connection numbers in 1000000xxx range on a 11.0.1 database, started five days earlier, with no activity since the period just after they were started. No identifying information at all. Probably not events or web services.

[VolkerBarth]

You're on 12.0.1 already? Cutting Edge, I have to say:)

[Breck_Carter]

More evidence of advancing years...

[VolkerBarth]

That gives the "diagnostics" tag a further meaning:)

[graeme_perrow]

There are a bunch of things that can cause temporary connections to be created. The list is on dcx on the connection properties page - look for the 'Name' property.

If your server is idle, it is very likely the cleaner.

[Breck_Carter]

This is actually 11.0.1 (sorry for misleading "12.0.1" in my question). There was nothing showing in the connection name column, were the names added in version 12?

[graeme_perrow]

Yes, the names are a new 12.0 feature.