Greetings, I'm investigating the use of PostgreSQL to maintain a database of mapping data. My dataset currently stored latitudes and longitudes as fixed-precision integers (ie, 37.234 is stored as 37234) in separate columns: one for latitude, one for longitude. Postgres has geometric data types, such as point, line, etc, but I'm a little leary of using them because of performance reasons. For one, the internal representation of a point is a pair of double-precision floating point numbers. For a dataset containing millions of points, working with floats could be expensive, both in storage and computation costs. Second, I want to be able to do queries like "find all line segments (or points) that overlap or intersect with a given bounding box." I'm afraid that without an appropriate index on the set of data points, a query like that will be extremely slow. So my questions are: what data structure is used to index a set of points? Is it a spatially-oriented structure, such as a quadtree, that would make queries like the example above very fast? Can Postgres be adapted to use integers instead of floats to store point coordinates? Thanks! Barry
