  Geographic location search engines allow users to constrain and order search
results in an intuitive manner by focusing a query on a particular geographic
region. Geographic search technology, also called location search, has recently
received significant interest from major search engine companies. Academic
research in this area has focused primarily on techniques for extracting
geographic knowledge from the web. In this paper, we study the problem of
efficient query processing in scalable geographic search engines. Query
processing is a major bottleneck in standard web search engines, and the main
reason for the thousands of machines used by the major engines. Geographic
search engine query processing is different in that it requires a combination
of text and spatial data processing techniques. We propose several algorithms
for efficient query processing in geographic search engines, integrate them
into an existing web search query processor, and evaluate them on large sets of
real data and query traces.
