Oracle8 Spatial Cartridge User's Guide and Reference
Release 8.0.4

A53264-02
 Library Product Contents Index

# Glossary

##### area

An extent or region of dimensional space.

##### attribute

Descriptive information characterizing a geographical feature such as a point, line, or area.

##### attribute data

Nondimensional data that provides additional descriptive information about multidimensional data, for example a class or feature such as a bridge or a road.

##### boundary
1. The lower or upper extent of the range of a dimension, expressed by a numeric value.
2. The line representing the outline of a polygon.
##### Cartesian coordinate system

A coordinate system in which the location of a point in n-dimensional space is defined by distances from the point to the reference plane. Distances are measured parallel to the planes intersecting a given reference plane.

##### contain

To describe a geometric relationship where one object encompasses another and the inner object does not touch any boundaries of the outer. The outer object contains the inner object. See also inside.

##### coordinate

A set of values uniquely defining a point in an n-dimensional coordinate system.

##### coordinate system

A reference system for the unique definition for the location of a point in n-dimensional space.

##### cover

To describe a geometric relationship in which one object encompasses another and the inner object touches the boundary of the outer object in one or more places.

##### data dictionary

A repository of information about data. A data dictionary stores relational information on all the objects in a database.

##### decompose

To separate or resolve into constituent parts or elements, or into simpler compounds.

##### dimensional data

Data that has one or more dimensional components and is described by multiple values.

##### disjoint

A geometric relationship where two objects do not interact in any way. Two disjoint objects do not share any element or piece of their geometry.

##### equal

A geometric relationship in which two objects are considered to represent the same geometric figure. The two objects must be composed of the same number of points, however, the ordering of the points defining the two objects' geometries may differ (clockwise or counter-clockwise).

##### extent

A rectangle bounding a map, the size of which is determined by the minimum and maximum map coordinates.

##### feature

An object in a spatial database with a distinct set of characteristics.

##### geographically referenced data

See spatiotemporal data.

##### georeferenced data

See spatiotemporal data.

##### geographical information system

A computerized database management system used for the capture, conversion, storage, retrieval, analysis, and display of spatial data.

##### GIS

See geographical information system.

##### grid

A data structure composed of points located at the nodes of an imaginary grid. The spacing of the nodes is constant in both the horizontal and vertical directions.

##### HHCODE

A data type representing the intersection point of multiple dimensions. It encodes these multiple dimensions into a unique, linear value. The HHCODEs are used for both spatial indexing and partitioned point data.

##### high-water mark

Expressed in number of records and associated with Spatial Cartridge partitioned table structure, it defines the maximum number of records to store in a table before decomposing another level. The high water mark determines the maximum size of a partition within the Spatial Cartridge table. Partitioned tables are an alternative to spatial indexing.

##### hole

A polygon can include subelements that negate sections of its interior. For example, consider a polygon representing a map of a buildable land with an inner polygon (a hole) representing where a lake is located.

##### homogeneous

Spatial data of one feature type such as points, lines, or regions.

##### hyperspatial data

In mathematics, any space comprising more than the three standard x, y, and z dimensions, also referred to as multidimensional data.

##### index

Identifier that is not part of a database and used to access stored information.

##### inside

To describe a geometric relationship where one object is surrounded by a larger object and the inner object does not touch the boundary of the outer. The smaller object is inside the larger. See also contain.

##### key

A field in a database used to obtain access to stored information.

##### keyword

Synonym for reserved word.

##### latitude

North/South position of a point on the Earth defined as the angle between the normal to the Earth's surface at that point and the plane of the equator.

##### line

A geometric object represented by a series of points, or inferred as existing between two coordinate points.

##### longitude

East/West position of a point on the Earth defined as the angle between the plane of a reference meridian and the plane of a meridian passing through an arbitrary point.

##### multidimensional data

See hyperspatial data.

##### partition
1. The spatial table that contains data only for a unique bounded n-dimensional space.
2. The process of grouping data into partitions that maintain the dimensional organization of the data.
##### partition key column

The primary HHCODE column that is used to dimensionally partition the data. One HHCODE data type column must be identified as the partition key for the table to be registered as partitionable in the Spatial Cartridge data dictionary. There can only be one partition key per spatial table. Note that this is only used for partitioned point data, and not spatially indexed data.

##### partitioned table

The spatial logical table structure that contains one or more partitions. Use partitioned tables only if you are dealing with a very large amount of point data (over 50 GB).

##### polygon

A class of spatial objects having a nonzero area and perimeter, and representing a closed boundary region of uniform characteristics.

##### proximity

A measure of inter-object distance.

##### query

A set of conditions or questions that form the basis for the retrieval of information from a database.

##### query window

Area within which the retrieval of spatial information and related attributes is performed.

##### RDBMS

See Relational Database Management System.

##### recursion

A process, function, or routine that executes continuously until a specified condition is met.

##### region

An extent or area of multidimensional space.

##### Relational Database Management System (RDBMS)

A computer program designed to store and retrieve shared data. In a relational system, data is stored in tables consisting of one or more rows, each containing the same set of columns. Oracle8 is a relational database management system. Other types of database systems are called hierarchical or network database systems.

##### resolution

The number of subdivision levels of data.

##### scale
1. The number of digits to the right of the decimal point in a number representing the level of resolution of an HHCODE.
2. The ratio of the distance on a map, photograph, or image to the corresponding image on the ground, all expressed in the same units.
##### SD*Converter

A utility used with previous versions of Spatial Data Option to load formatted data into spatial tables. Loading is now accomplished through SQL*Loader.

##### sort

The operation of arranging a set of items according to a key that determines the sequence and precedence of items.

##### spatial

A generic term used to reference the mathematical concept of n-dimensional data.

##### spatial data

Data that is referenced by its location in n-dimensional space. The position of spatial data is described by multiple values. See also hyperspatial data.

##### spatial database

A database containing information indexed by location.

##### spatial data model

A model of how objects are located on a spatial context.

##### Spatial Cartridge data dictionary

An extension of the Oracle8 data dictionary. It keeps track of the number of partitions created in a spatial table. The Spatial Cartridge data dictionary is owned by MDSYS. The data dictionary is used only by the partitioned point routines.

##### spatial data structures

A class of data structures designed to store spatial information and facilitate its manipulation.

The format used to load data into spatial tables in a previous version of Spatial Data Option. Loading is now accomplished with the standard SQL*Loader.

##### spatial query

A query that includes criteria for which selected features must meet location conditions.

##### spatiotemporal data

Data that contains time and/or location components as one of its dimensions, also referred to as geographically referenced data or georeferenced data.

##### tessellation

The process of covering a geometry with rectangular tiles without gaps or overlaps.

##### tiling

See tessellation.

##### touch

To describe a geometric relationship where two objects share a common point on their boundaries, but their interiors do not intersect.