Ludwi's questions

My company is really sensitive about keeping up the performance on our core system. Our users also have a requirement to replicate or mirror all data to another location (in another location within city limits) in case a disaster happens. A software vendor came up with a proposal to implement GoldenGate system.

I'm having trouble believing the proposal saying it will have no impact on performance because it utilizes the log that is written during database write. They keep saying that reading the log will have no impact on the server performance. I know for sure writing the log does though.

Also doesn't data transfer from the source to the destination impact the performance of the source server? I'm a beginner at this. Does communication through sockets really have no impact on the source server?

Is there a better way to mirror data without sacrificing performance, at all?

A couple of our servers have Oracle maintenance licenses. Our hardware vendor asked there was internet connection in the server room. Our policy is that all machines in that room is isolated from the internet for security reasons. But the maintenance guy asked "then how are we going to be able to do maintenance work on your servers?"

My question is, do our servers need internet connection in order for the maintenance to be carried out like a license verification system. Or can he do it offline? Isn't it a risk in itself if there was an internet connection to our production server?