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README.md

Relational GIS Data Model Template

The NENA NG9-1-1 GIS Data Model Section 15 Appendix E-Relational Data Model outlines the relational data model utilized in the SI (Spatial Interface). Apart from primary and foreign keys, the Descriptive Names used in Appendix E align with those listed in Section 5 Detailed Description of Field Names and Associated Attribute Data.

Due to various SQL dialects, the relational database model is currently represented as a logical, rather than a physical, data model. A logical model focuses on structure, relationships, and rules, independent of any specific database technology, whereas a physical model focuses on how the database will is implemented in a specific database.

NOTE: The relational data model adopted in NENA-STA-006.3-2026 supersedes the PostgreSQL/PostGIS "flat-file" template provided in previous versions.



Folders and Files

  • schema - Folder containing the NENA NG9-1-1 GIS relational data model schema organized by version.
    • v3.0 - Folder containing the v3.0 release of the NENA GIS relational data model.
      • .imgs - Folder containing documentation images and screenshots.
      • README.md - README file for v3.0 release.
  • README.md - This document.

Data Type Mapping

The relational data model is a logical data model, not a physical data model, and will require mapping data types to database specific datatypes. The following table provides examples of cross‑platform data type equivalency for reference purposes only.

NENA-STA-006 Relational Data Model PostgreSQL MS SQL Server Esri FGDB geoPackage
TEXT(Length) TEXT(n) VARCHAR(n) VARCHAR(n) TEXT(n) TEXT
DATETIME DATETIME TIMESTAMPZ DATETIMEOFFSET DATE DATETIME
INTEGER INTEGER INTEGER INTEGER LONG INTEGER
REAL(p,s) REAL(p,s) NUMERIC(p,s) NUMERIC(p,s) DOUBLE REAL
Not Defined BIGINT1 BIGSERIAL/BIGINT BIGINT OBJECTID INTEGER
Not Defined GEOMETRY(POINT) GEOMETRY(POINT) GEOMETRY::POINT POINT POINT
Not Defined GEOMETRY(LINESTRING) GEOMETRY(LINE) GEOMETRY::LINESTRING POLYLINE LINESTRING
Not Defined GEOMETRY(POLGYON) GEOMETRY(POLYGON) GEOMETRY::POLYGON POLYGON POLYGON

1 The BIGINT data type is used to identify primary and foreign key fields. When a BIGINT is used as a primary key, it should implement a sequencer or increment function. It is recommended BIGINT data types are defined as 8-byte integers.


Help

For assistance not provided within this repositories documentation, please visit https://www.nena.org/page/DevelopmentGroup where contact information for the leadership of the Data Structures & Management Committee can be found.


Contributors

  • v3.0
    • Relational Database Subgroup

Acknowledgements

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