Introduction to Spatial

This chapter describes basic concepts of Tibero Spatial.

Tibero Spatial provides functions to save and use spatial data in Geographic Information Systems (GIS) and circuit diagrams.

GEOMETRY Objects

Tibero Spatial supports seven types of GEOMETRY objects that comply with the SQL-MM standard.

The following table describes each type of GEOMETRY objects. The object is saved as binary in Well Known Binary (WKB) format. Coordinates of GEOMETRY objects in the WKB format are saved as floating point numbers. Therefore, the result of calculations on the numbers may have some errors, and the result values may be different depending on the floating point calculation method.

Object Type	Description
POINT	Consists of one point. Zero-dimension.
LINESTRING	Consists of two or more points.
POLYGON	Consists of one external ring and zero or more internal rings. A ring has the same start and end points, and it indicates a line string that has no internal intersecting point. Intersections of internal rings must be a point or there must be no intersection.
MULTIPOINT	Consists of one or more points. Zero-dimension.
MULTILINESTRING	Consists of one or more line strings.
MULTIPOLYGON	Consists of one or more polygons.
GEOMETRYCOLLECTION	Consists of one or more GEOMETRY objects.

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Spatial Referencing System(SRS)

Tibero Spatial supports the following coordinate systems that calculate coordinates for depicting real space by connecting them with real space. Depending on which coordinate system GEOMETRY belongs to, the result value of Spatial functions may vary.

Cartesian Coordinate

A coordinate system in which a position in space is expressed on a two-dimensional plane or a three-dimensional space. It is useful when depicting a local space where the curvature of the earth is not revealed. In Spatial, SRID is not specified. GEOMETRY is basically operated in the Cartesian coordinate system. GEOMETRY without a specified SRID is calculated in this Cartesian coordinate system by default.

Spherical Coordinate (Geography coordinate)

A coordinate system in which a position in space is expressed on a two-dimensional spherical or ellipsoidal surface (spheroid). This system approaches the actual location through latitude and longitude. It is useful when accurately depicting global space. In general, a sphere or spheroid is used to express the actual position on the earth. The radius, major radius, and minor radius information of a sphere or spheroid used in this system depends on SRID given to GEOMETRY. You cannot individually store different spheroids for each GEOMETRY.

SRID(Spatial Reference Identifier)

Spatial provides SRID, which is the identifier type of the coordinate system. SRID has information about a specific coordinate system, including whether the coordinate system for GEOMETRY is the Cartesian coordinate system or the spherical coordinate system.