dbf

Census data formats

Generally found as part of shapefile datasets in GIS; DBF is a standard database file used to store tabular data.

DBF, short for Database File, is an encapsulation of dBase, a framework into which database tables are arranged. These files consist of columns and rows much as you would expect to find in any database. Each column is clearly defined by a name, a type (numeric, character, logical, date), and a specific field width whereas each record (row) denotes an individual line of data.

This data format is typically embraced in the GIS (Geographical Information Systems) sector for shapefile databases. ESRI (Environmental Systems Research Institute) introduced shapefile as a geospatial vector data format for GIS software. Shapefile is a simple, non-topological format that stores the geometric location and attribute information of geographic features. The features are represented in points, lines, or polygons.

A Shapefile is actually a set of several associated files. These files have the same prefix name but different extensions. Out of these files, .shp contains the geometric data, .shx stores the index of the feature geometry, .prj holds the data's coordinate system information, while .dbf retains attributes for the features in the .shp file. The .dbf file can be opened in a variety of DBMS (Database Management Systems) including Oracle, MySQL, and Microsoft Access, or it can be viewed and modified using a text editor.

The .dbf file in a shapefile dataset stores the attribute data of geographic features. For example, in a shapefile database of a city's roads, the .shp file would store the geometric data (representing the physical shape and location of each road), while the .dbf file would store data such as the name of each road, type of road, length, and any other relevant information attached to each road.

DBF file format also furnishes an advantage in terms of size, as files stored can be significantly smaller compared to other database file formats. This makes it utilitarian for applications where compact storage is a necessity.

Despite its limitations in handling large datasets and lack of support for certain data types, the DBF format remains widely used due to its simplicity, wide support by diverse applications, and the integral role it plays in the shapefile data format in GIS.

Consequently, anyone working in GIS should be familiar with the ins and outs of the DBF data format, how it links to shapefile datasets, and what that means in terms of data manipulation and retrieval. With this understanding, GIS practitioners can harness the necessary data stored in shapefiles to make informed geographic decisions.