1. A computer-based method for determining information about an item from a database in response to an input uniform resource identifier (URI), comprising: receiving, with a computer, one of a number of input URIs having the same domain that reference the same item on web pages of the domain; determining a static portion of a prime URI from a database that associates a static portion with the domain of the input URI; retrieving, with the computer, a pre-computed regular expression that is associated with the domain of the input URI and that operates to produce a dynamic portion of the prime URI; applying, with the computer, the retrieved regular expression to the input URI to produce the dynamic portion of the prime URI; joining, with the computer, the static and dynamic portions of the prime URI to complete the prime URI and using the completed prime URI as a key to access an entry associated with the item in a database that stores information for the item from multiple domains, wherein the information includes a product ID; retrieving, with the computer, information about the item associated with the domain of the input URI using the prime URI and information about the item that is associated with one or more other domains using the product ID; and presenting the retrieved information for the item.