I want to put the coordinates of cities in a spatial db and then find cities from a given city at some given distance. I am hoping these functions would be readily available in a spatial db like PostGis. First, am I right in assuming this?
The problem I am facing though is this - I do not know where to store these coordinates from. I have this with me - http://download.geonames.org/export/dump/ and it has a 290 mb file (allcountries.zip) with coordinates of all cities but I am not sure how accurate it is. I am going to use this data to build something important so I want to know if someone here uses something more accurate or concise.
If the cities are much farther apart, just the latitudes and longtitudes won't do right? Will need something like spatial ref Ids also? Please suggest the right approach.
Also, given so much info, how does one proceed to find cities from a given city and given distance?