1) I have a table with information about prices. The prices change a lot, so i insert new information about them every few seconds. I want to do a SELECT with the price for every product. When every timestamp would be the same it would be easy, but how do i do this when the highest timestamp for every product differs?
2) I want to archive my price information, but don't need an entry for every second, an hour would be enough. Is there an easy way to remove entries if threre is alreays an entry for a specified hour?