在内存中共享大数据表?

I have a few table frequently used by my website. for example, largest one is a location table which is holding massive static data. So anytime users come over my website, they do search for within these locations. It holds around 1.5 million rows. I have sized this table using memory profiler and it is nearly 500mb in the memory. eventually I have a few more static tables those I need to access very quickly and they are static. at the end my memory dump gets up to 1,5 gb memory usage. which is not a problem for me while I have a powerful server with a lot of memory available. but when I raise that question, senior developers and architectures are telling me that I should review my project because a process shouldn't occupy that much memory. But I need quick access, I don't want to query my DB every time. I need response under 1 sec. Thats why memory looks like the way for me. Is there any better advise ? I have a few table frequently used by my websit