Dealing with duplicated or repeated spaces

As we can't uniquely identify each space with some field or value, we have to develop a method or process to identify when data may be repeated in the database. I'm currently working in some schemes that may be useful for this task namely fuzzy hashing and searching in near places by latitude and longitude. I'll go into more detail in a README I'm writing but I think I'll be good to get the conversation going about this issue in this thread, so more ideas about this are welcome.