(mysql.info) gis-introduction

(mysql.info) opengis-geometry-model
 
 16.1 Introduction to MySQL Spatial Support
 ==========================================
 
 MySQL implements spatial extensions following the specification of the
 Open Geospatial Consortium (OGC). This is an international consortium
 of more than 250 companies, agencies, and universities participating in
 the development of publicly available conceptual solutions that can be
 useful with all kinds of applications that manage spatial data. The OGC
 maintains a Web site at `http://www.opengis.org/'.
 
 In 1997, the Open Geospatial Consortium published the `OpenGIS(R)
 Simple Features Specifications For SQL', a document that proposes
 several conceptual ways for extending an SQL RDBMS to support spatial
 data. This specification is available from the OGC Web site at
 `http://www.opengis.org/docs/99-049.pdf'. It contains additional
 information relevant to this chapter.
 
 MySQL implements a subset of the *SQL with Geometry Types* environment
 proposed by OGC. This term refers to an SQL environment that has been
 extended with a set of geometry types. A geometry-valued SQL column is
 implemented as a column that has a geometry type. The specification
 describe a set of SQL geometry types, as well as functions on those
 types to create and analyze geometry values.
 
 A *geographic feature* is anything in the world that has a location. A
 feature can be:
 
    * An entity. For example, a mountain, a pond, a city.
 
    * A space. For example, a postcode area, the tropics.
 
    * A definable location. For example, a crossroad, as a particular
      place where two streets intersect.
 
 Some documents use the term *geospatial feature* to refer to geographic
 features.
 
 *Geometry* is another word that denotes a geographic feature.
 Originally the word *geometry* meant measurement of the earth. Another
 meaning comes from cartography, referring to the geometric features
 that cartographers use to map the world.
 
 This chapter uses all of these terms synonymously: *geographic feature*,
 *geospatial feature*, *feature*, or *geometry*. Here, the term most
 commonly used is *geometry*, defined as _a point or an aggregate of
 points representing anything in the world that has a location_.
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(mysql.info) spatial-extensions
(mysql.info) opengis-geometry-model
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