Administration: Omnidex Features

Geographic Searches

Overview | Latitude and Longitude | Radius Distance Searches | Indexing | Optimization

Optimizing Geographic Searches

Geographic searches are specified using a $DISTANCE function. As long as there is a multi-column Omnidex index containing the latitude and longitude, the $distance function will be automatically optimized.

Examples

The following are examples of several types of geographic searches that can be optimized using the $distance function.

Example 1: Distance between two sets of coordinates

SELECT      $distance(40.0, -105.0, 41.0, -106.0) distance
  FROM      $omnidex;

Example 2: Distance between two sets of coordinates using columns

SELECT      zip,
            $distance(40.0, -105.0, latitude, longitude) distance, 
            latitude, longitude,
  FROM      zipcodes
 WHERE      $distance(40.0, -105.0, latitude, longitude) < 10;

Example 3: Distance between an origin and multiple sets of destination coordinates

SELECT      state, zip, latitude, longitude
   FROM      zipcodes
  WHERE      $distance(latitude, longitude,
                       (SELECT      latitude, longitude
                          FROM      zipcodes
                         WHERE      state = 'CO')) < 5;

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