224
© 2016 Open Geospatial Consortium
Requirements Class - Vector datasets Mandatory Attribute Usage 113-116 req
coretiled-vector-datasets-mandatory-attributes Target type
Operations Dependency
Various XML schema Requirement 113
req
core
mandatory-attribute-compliance Requirement 114
reqcoreoptional-attribute-compliance Requirement 115
reqcore
dataset-instance-schema
Requirement 116 reqcore
attributes-metadata
5.7.1.2.1 Attribute Code
A unique four-digit numeric code is associated to each attribute. For example, the attribute Angle of Orientation has an attribute code of “0003”.
5.7.1.2.2 Attribute Identifier
A unique three-character or four-character alphanumeric identifier is associated to the attributes that are governed by this standard. Attributes other than those governed by the CDB standard
may not have an assigned identifier. For example, the CDB attribute Length has the “LEN” identifier. The identifier is a case-sensitive string of up to 10 characters. In the case of instance-
level and class-level attributes, the identifier is used as the base name for a column name, such as counties.dbf, in a vector attribute encoding.
5.7.1.2.3 Attribute Semantics
Each attribute is associated with a textual description describing semantic information, which provides a human readable definition of the attribute.
5.7.1.2.4 Attributes Values
A value can be assigned to each attribute. The data type, length, format, range, usage, units, compatibility and schema of each attribute value is governed by this standard. Attribute values
give quantitativequalitative meaning to the attribute.
5.7.1.2.5 Attribute Usage
CDB attribution usage falls in the following categories:
Requirement 113 Mandatory Attribute Usage
225
© 2016 Open Geospatial Consortium
http:www.opengis.netspeccdb1.0coremandatory-attribute-compliance
A CDB compliant vector dataset SHALL have no missing mandatory attributes. See Section 5.7.1.3 for Mandatory attributes and their characteristics.
Clarification note Mandatory: A mandatory attribute is an attribute whose value SHALL be provided for all of the features of a specified dataset, i.e., a producer of CDB data e.g.,
tools is required to generate values for mandatory attributes. Consumers of CDB compliant data tools andor simulator client-devices can rely on the availability of
mandatory attributes.
Recommended: A recommended attribute is an attribute whose value should be provided for all of the features of a specified dataset. Consumers of CDB compliant data tools andor simulator
client-devices can always rely on the availability of recommended attributes since the attribute value is either provided explicitly in the CDB data storedataset or provided implicitly as a
defaulted value in accordance to section 5.7.1.3, CDB Attributes. A CDB with defaulted recommended attributes is considered compliant by this standard; however, the performance of
one or more of the client-devices commonly found on simulation devices may be adversely affected.
Optional: An optional attribute is an attribute whose value may optionally be provided for all of the features of a specified dataset. Consumers of CDB compliant data tools andor simulator
client-devices cannot rely on the availability of optional attributes.
Requirement 114 Missing optional attributes
http:www.opengis.netspeccdb1.0coreoptional-attribute-compliance
A CDB dataset with missing optional attributes SHALL be considered compliant by this standard; however, the performance of one or more of the client-devices commonly
found on simulation devices may be enhanced by including the optional attributes. See Section 5.7.1.3 for Optional attributes and their characteristics.
Dependent: A dependent attribute is an attribute whose value depends on another attribute, be it mandatory, recommended, or optional. The attribute is considered mandatory if the attribute it
depends on is mandatory. Likewise, the attribute is considered recommended if the attribute it depends on is recommended. Finally, the attribute is considered optional if the attribute it
depends on is optional.
226
© 2016 Open Geospatial Consortium
Note that attribute usage information for each of the CDB attributes can be found in section 5.7.1.3, CDB Attributes and in Table 5-27: Allocation of CDB Attributes to Vector Datasets
5.7.1.2.6 Attribution Data Compatibility
