Relational Schema

The VC Database v5 is a major revision of the previous v4 release. The database schema has been completely redesigned, significantly simplified, and restructured. Unlike v4, it no longer uses individual feature tables with dedicated attribute columns. Instead, the schema is streamlined with fewer tables, including a single FEATURE table for storing all features and objects, and a single PROPERTY table that holds most attributes and associations.

image relationalSchema
Figure 1. Relational Schema of the VCDB v5.

All tables of the relation schema are logically grouped into five modules, which are discussed in the following chapters:

  • Feature Module: Contains the core tables for storing feature information, excluding geometry and appearance data.

  • Geometry Module: Contains tables for storing both explicit and implicit geometry data.

  • Appearance Module: Contains tables for storing appearance information.

  • Metadata Module: Holds meta-information about features and their properties.

  • Codelist Module: Stores codelists with their corresponding values.

Although conceptually the database model is applicable to any database system, this chapter uses PostgreSQL-specific figures and examples.