I'm not sure if this is the right forum for what is basically a construction question, but I am hoping someone can help me.

We have a concrete patio on the south side of our house. It's kind of an odd space. There's not much room from the edge of the patio to the edge of our property, maybe four feet. With heat reflected off the house and slab, it is too hot to spend any time there. We were thinking of installing an arbor and training a grapevine over it.

We have never built anything like this. We think it would be best to anchor one side of the arbor to the house and the other side to the ground via posts. It's the posts I'm wondering about.

I have done some reading online and came across a builder with a similar situation who drilled holes directly into the concrete of the patio, installing metal post supports to keep the wooden arbor posts off the ground and building from there. What does this look like? Is it secure?

Other builders drill into the ground (beyond the concrete pad, I suppose?) and attach the posts that way. This seems more stable to me (is it?), but with such a small stretch of lawn past the patio I'm hoping we could put the posts really, really close to the patio so that we could still open our gate. Also, I think this would be kind of odd-looking.

Has anyone ever put an arbor in over an existing patio like this?