Systems and methods to store, in a database, product information identifying each respective product in the database, a store in the shopping mall that carries the respective product, and a location within the store where the respective product is physically accessible by a customer visiting the mall. The database is updated via communicating with database systems of stores in the mall and/or dispatching robots to the stores to collect data for the updates. Frequencies of the updates are determined based on sales volumes of the stores. A server is used to provide a user interface to access the database of the mall and provide navigational guidance for travel from current locations of user devices and the locations of the items.