Only one database and only one domain. It's just the communication between 'user agent' and server that's affected.
If i hosted one website on HTTP and after i want to provide security to the same site then two copies of same site will generate or there is only one copy for both HTTP and HTTPS? I tried to search about this but i didn't get the proper answer i want to know that there is different database for HTTP and HTTPS?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic