Methods and systems for selecting and providing a relevant subset of Wi-Fi location information to a mobile client device so the client device may estimate its position with efficient utilization of resources.A method of providing a relevant subset of information to a client device is based in part on scanning for Wi-Fi access points within range of the client device, using a Wi-Fi database that covers a large target region to retrieve information about these access points, using this information to estimate the position of the mobile client device, selecting a limited region in the vicinity of the estimated location of the client device, and providing information about Wi-Fi access points within this limited region to the client. For efficient transfer and maintenance of data, the target region may be divided into a hierarchy of fixed geographical tiles.