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dBASE Table File Format (DBF)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name dBASE Table File Format (DBF)
Description File format used originally by the dBASE database management system to store tables of data and later adopted by similar DBMS packages. The file format was appealing because of its combination of a simple structure and support for data types appropriate for business use. It is best suited to fixed-field data. For the same reasons, it was adopted by specialist software developers as a simple format for storing fixed field tables of textual and numeric data. The format is not completely and publicly documented, and the format used by later versions of dBASE software has been extended to support new functionality.
Relationship to other formats
    Has subtype MapInfo_DAT, MapInfo Data File (DAT). Constrained form of DBF used for the mandatory component file in a MapInfo Dataset that holds a table of attribute data.
    Has subtype Shape_DBF, dBASE Table for ESRI Shapefile (DBF). ESRI adopted a constrained DBF format for storing tabular data. For example, a Shape_DBF instance shall not include Memo fields or other variable-length data types, such as BLOBs (Binary Large Objects).
    Has subtype Other geospatial formats use files in this format as components of a format that comprises multiple related files, including PC ArcInfo Coverage files. The constraints on the DBF for PC ArcInfo Coverage are believed to be similar to those for ESRI Shapefiles (Shape_DBF).

Local use Explanation of format description terms

LC experience or existing holdings None
LC preference None. The Library of Congress has not collected databases through copyright deposit and has therefore not declared a preference.

Sustainability factors Explanation of format description terms

Disclosure A proprietary format, with only the current version documented by dataBased Intelligence, Inc., the company responsible for the current version of dBASE. Earlier versions are documented unofficially.
    Documentation

Data File Header Structure for the dBASE Version 7 Table File documents the table file format for version 7 of dBASE (current as of February 2011).

Earlier versions are documented unofficially in Xbase File Format Description and DBase File Structure.

Adoption

The DBF file format was adopted by other database management system developers, as is evidenced by the following list of filetype identifiers:

  • 0x02 FoxBASE
  • 0x03 FoxBASE+/Dbase III plus, no memo
  • 0x30 Visual FoxPro
  • 0x31 Visual FoxPro, autoincrement enabled
  • 0x32 Visual FoxPro with field type Varchar or Varbinary
  • 0x43 dBASE IV SQL table files, no memo
  • 0x63 dBASE IV SQL system files, no memo
  • 0x83 FoxBASE+/dBASE III PLUS, with memo
  • 0x8B dBASE IV with memo
  • 0xCB dBASE IV SQL table files, with memo
  • 0xF5 FoxPro 2.x (or earlier) with memo
  • 0xE5 HiPer-Six format with SMT memo file
  • 0xFB FoxBASE

The DBF file format has also been adopted as a component of data storage or exchange formats in specialist areas, such as the geospatial formats Shapefile, Coverage, and MapInfo.

    Licensing and patents The compilers of this resource are unaware of any current licensing issues. In 1988, Ashton-Tate, the owners of the dBASE product at the time, sued FoxBase for copyright infringement, but was unsuccessful. See Wikipedia article on dBASE.
Transparency Depends on the types of data stored. The values in a DBF file consisting of fixed-length character fields (data type C) and fixed length numeric fields stored as strings (data type N) can be viewed with a text editor.
Self-documentation The format embeds the names and types of data fields within the data file.
External dependencies None
Technical protection considerations None

Quality and functionality factors Explanation of format description terms

Dataset
Normal functionality

One important reason for the adoption of .dbf files as a data storage and exchange format, was its support for a variety of data types, useful in business and some scientific contexts. Data types for dBASE III through dBASE 5 are described at http://www.clicketyclick.dk/databases/xbase/format/data_types.html.

Data types supported in the current (as of February 2011) version of dBASE are documented at http://www.dbase.com/Knowledgebase/INT/db7_file_fmt.htm.

The fundamental structure of a .dbf file is a table.

Support for software interfaces (APIs, etc.) There are many applications that can view or use .dbf files, including software libraries that implement programming languages that are compatible with and/or derived from the dBASE programming language. There is not a single widely supported or standard API tor software library for querying or subsetting .dbf files.
Data documentation (quality, provenance, etc.) No inherent support for metadata or data documentation.

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension .dbf
 
Internet Media Type application/dbase
application/x-dbase
application/dbf
application/x-dbf
Found at Filext.com. Not registered at IANA.

Notes Explanation of format description terms

General If present, variable-length fields, such as binary and memo fields are stored in a separate .dbt field. The values in the .dbf file are index 10-byte entries into the .dbt file. Such data types are not supported in many applications of the DBF format in contexts unrelated to dBASE or other general-purpose database management systems.
History

The dBASE format was an early Database Management System (DBMS) for personal computers. dBASE II was available for CP/M, Apple II and DOS in the early 1980s. A major upgrade to dBASE III in 1984 allowed more convenient porting to other operating systems, including UNIX and VMS. Several clone products appeared, using the same data file format. dBASE IV was released in late 1988. The dBASE product lost market share to competitors by being late to market with a version of dBASE for Windows. By this time, the .dbf file format had an independent existence. The term xBase (or Xbase or XDB) is used to refer to programming languages and compatible software that derive from the original dBASE language and products.

On April 2nd 2012, after a corporate re-organization, dBase LLC was introduced. Recognizing its importance as a legacy application platform and format, they have made it easier to use old database applications and associated workflows. A new product is a virtual machine product, dbDOS, which allows DOS versions of dBASE to run on Windows; re-packaged is dBASE Classic, which runs under dbDOS and corresponds to dBASE 5.0 for DOS, which was released in 1994. The new package includes all manuals as searchable PDFs. As of October 2012, there is no timeline for the next version of dBASE for Windows; the current version is 2.8.


Format specifications Explanation of format description terms


Useful references

URLs

Books, articles, etc.

Last Updated: 11/13/2013