Metadata Directory \CDB\Navigation\:

83 © 2015 Open Geospatial Consortium Materials, for a description of the CDB materials. A listing of the CDB Base Materials can be found in Appendix L. The base material names found in appendix L must be used when the “Materials.xml” file is not found in the metadata directory. Refer to section 5.1.3 Base Material Table for a description of the materials definition file. 4. “Defaults” Definitions Metadata file: This file contains the default values for each of the CDB datasets. Refer to Chapter 5, CDB Datasets, for a description of the CDB datasets. Appendix S lists the various default values as documented throughout this Specification. Defaults values found in appendix S must be used if the “Defaults.xml” file is not found in the metadata directory. Refer to section 5.1.4 Default Values Definition Metadata for a description of the defaults definition file. 5. “Specification_Version” Metadata file deprecated 6. “Version” Metadata file: This metadata file is mandatory and identifies the content of one CDB Version. The concept is described in section 3.2.1, CDB Version; the content of the file is defined in section 5.1.6, Version Metadata. 7. “CDB_Attributes” Metadata file: This file is used to describe all the CDB attributes that are supported by the CDB Specification. A complete listing and description of CDB attributes is provided in section 5.7.1.3, CDB Attributes of this Specification. The file is described in section 5.1.7 CDB Attributes Metadata. 8. “Geomatics_Attributes” Metadata file: This file is used to describe all Geomatics attributes that may be referenced by this CDB refer to section 5.7.1.2.6.2, Geomatics Attributes for a description of Geomatics attributes. Note that the usage of Geomatics attribution falls outside of the jurisdiction of the CDB Specification. Nonetheless, the CDB Specification provides a standardized mechanism to allow users to fully describe each of the Geomatics attributes they wish to insert within the CDB repository structure. The file is described in section 5.1.8, Geomatics Attributes Metadata. 9. “Vendor_Attributes” Metadata file: This file is used to describe all Vendor attributes that may be referenced by this CDB refer to section 5.7.1.2.6.3, Vendor Attributes for a description of Vendor attributes. Note that the usage of Vendor attribution falls outside of the jurisdiction of the CDB Specification. Nonetheless, the CDB Specification provides a standardized mechanism to allow users to fully describe each of the Vendor attributes they wish to insert within the CDB repository structure. The file is described in section 5.1.9, Vendor Attributes Metadata. 10. Client-specific Metadata files: These files are limited to “Lights_xxx.xml” Definitions Metadata files and offer a complementary approach to modifying the appearance of lights for 84 © 2015 Open Geospatial Consortium specific client-devices. The “xxx” suffix is a 32-character string placeholder that stands for the client-device name. There can only be one such file per client-device and the files for each client-device are optional. Refer to section 5.1.1.1, Client Specific Lights Definition Metadata for a description of the client specific lights definition file. 11. “Configuration” Metadata file: This file provides the means of defining CDB Configurations. The concept is defined in section 3.2.4, CDB Configuration; the content of the file is defined in section 5.1.10, Configuration Metadata.

3.1.2 Metadata File Examples

Each CDB Version has a metadata file whose complete path and file name is: \CDB\Metadata\Version.xml A Forward Looking Infrared client device named “FLIR” has a client specific metadata file having the following directory path and file name: \CDB\Metadata\Lights_FLIR.xml

3.2 CDB Configuration Management

The CDB Configuration and CDB Version mechanisms allow users to manage the Common Database CDB. The two mechanisms permit the users to implement Configuration Management CM and versioning by offering the following capabilities: ฀ The Common Database CDB can have multiple simultaneous independent CDB Configurations. ฀ Each CDB Configuration is defined by an ordered list of CDB Versions. ฀ A CDB Version is either a collection of pure CDB Datasets or a collection of user-defined datasets o in which case the CDB Version is called a CDB Extension

3.2.1 CDB Version

A CDB Version is a collection of pure CDB Datasets andor user-defined datasets. A CDB Version contains data belonging to a single version of the Specification. A CDB Version may refer to another CDB Version. This is the basis for the CDB File Replacement Mechanism. The concept of a CDB Version is illustrated by the UML diagram below. 85 © 2015 Open Geospatial Consortium - atasets - Specification ersion - ersion C B Version -data CDB Dataset Figure 3-1: UML Diagram of CDB Version Concept The diagram shows that a CDB Version contains CDB Datasets; in addition it states which CDB Specification Number has been used to build the CDB content; finally, the CDB Version has a reference to another CDB Version. This reference allows the creation of a chain of CDB Versions. By chaining two CDB Versions together, the user can replace files in a previous CDB Version with new ones in a newer CDB Version. The figure below illustrates the chaining of CDB Versions belonging to different CDB Specification Number. ersion ersion Spec Spec ersion Spec Figure 3-2: A Valid Chain of CDB Versions The figure above shows three 3 CDB Versions, each containing data compliant to a different version of the Specification. It shows that CDB Version 3 on the left complies with version 3.2 of the Specification and refers the blue line to CDB Version 2 in the middle, a 3.1-compliant database, which in turn refers to CDB Version 1 to the right, a 3.0-compliant database. Each CDB Version has its own Version.xml file in its Metadata folder. As such, the smallest CDB Version contains a single file: \CDB\Metadata\Version.xml