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149:
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While a user can write a table of contents into a text file, the text file format itself does not include a concept of a table of contents. While a user may write "friends with Kathy" in the "Notes" section for John's contact information, this is interpreted by the user rather than a built-in feature
388:
With predefined lengths, fields are limited to a maximum length. The need for longer fields may appear sometime after the format is defined. Possible workarounds include abbreviating phrases, replacing values with links (e.g. a URI pointing to the value), and splitting a file into multiple files.
364:
If the delimiter is allowed inside a field, there needs to be a way to distinguish delimiters characters or strings that are meant literally. For example, consider the sentence "If I have to, I'll do it myself.". To encode it in CSV, there needs to be a way to prevent the comma from splitting the
488:
data, primitive spreadsheets (perhaps comma-separated or tab-delimited), and text files can all be seen as flat-file databases because they lack integrated indexes, built-in references between data elements, and complex data types. Programs to manage collections of books or appointments and
497:
of the database. When a database system begins to recognize and codify relationships between records, it begins to drift away from being "flat," and when it has a detailed system for describing types and hierarchical relationships, it is now too structured to be considered "flat."
431:, involving data tabulated via hole punches in paper cards, is sometimes considered the first computerized flat-file database, as it included no cards indexing other cards, or otherwise relating the individual cards to one another, save by their group membership.
594:
Since the formal operations possible with a text file are usually more limited than desired, the text in the above example would ordinarily represent an intermediary state of the data prior to being transferred into a
534:
id name team 1 Amy Blues 2 Bob Reds 3 Chuck Blues 4 Richard Blues 5 Ethel Reds 6 Fred Blues 7 Gilly Blues 8 Hank Reds 9 Hank Blues
656:
396:. This is not needed for fixed-width formats. However, fixed-width formats can lead to unnecessarily large file sizes if fields tend to be shorter than the lengths reserved for them.
537:
This type of data representation is quite standard for a flat-file database, although there are some additional considerations that are not readily apparent from the text:
225:. Records follow a uniform format, and there are no structures for indexing or recognizing relationships between records. The file is simple. A flat file can be a
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characters. This is also called indentation or "fixed-width" data formatting. Another common convention is to separate columns using one or more
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may use single-purpose flat-file databases, storing and retrieving information from flat files unadorned with indexes or pointing systems.
245:. Relationships can be inferred from the data in the database, but the database format itself does not make those relationships explicit.
294:
A list of names, addresses, and phone numbers written by hand on a sheet of paper is a flat-file database. This can also be done with any
472:
Flat-file databases are common and ubiquitous because they are easy to write and edit, and suit myriad purposes in an uncomplicated way.
64:
381:
as needed. The fixed lengths can be predefined and known ahead of time (i.e. stated in the format's specification), or parsed from a
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446:. These programs were designed to make it easy for individuals to design and use their own databases, and were almost on par with
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83:
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412:. It has low overhead and trivially avoids delimiter collisions, but it is brittle when edited manually and is rarely used.
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548:. Such restrictions are usually established by convention, but not formally indicated unless the data is transferred to a
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With delimiter-separated formats, determining the field boundaries requires finding the delimiters, which incurs some
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WTEC'94: Proceedings of the USENIX Winter 1994 Technical
Conference on USENIX Winter 1994 Technical Conference
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357:(delimiter is the tab character), space-separated values, and vertical-bar-separated values (delimiter is
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each column in a database table such as the one above is ordinarily restricted to a specific
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operating systems. Another example of a flat file is a name-and-address list with the fields
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584:(the above example depicts a series of 3-tuples). Additionally, the first row specifies the
420:
248:
The term has generally implied a small database, but very large databases can also be flat.
31:
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Delimiters can be used alongside a notation stating the length of each field. For example,
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program may be used to implement a flat-file database, which may then be printed or used
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With fixed-width formats, each column has a fixed length, and fields are padded with
524:(the name of an athletic team supported by the person, third column); and a numeric
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in popularity. Examples of flat-file database software include early versions of
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The following example illustrates typical elements of a flat-file database. The
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Each row or record in the above table meets the standard definition of a
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arrangement consists of a series of columns and rows organized into a
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177:. Statements consisting only of original research should be removed.
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Here is an example textual representation of the described data:
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In the above example, individual columns are separated using
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specifies the length (5 and 9) of each field. This is called
612:, a commonly used flat file, used to detail users in Unix
166:
528:, (used to uniquely identify records, first column).
265:
863:
827:
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71:. Unsourced material may be challenged and removed.
345:are separated by a character or string called the
271:
663:, U.S. Department of Transportation, August 2001.
588:that are associated with the values of each row.
27:Database stored as an ordinary unstructured file
691:Blodgett, John H.; Schultz, Claire K. (1969).
434:In the 1980s, configurable flat-file database
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513:. This specific example uses only one table.
8:
693:"Herman hollerith: data processing pioneer"
749:
735:
727:
367:strategies to prevent delimiter collision
193:Learn how and when to remove this message
131:Learn how and when to remove this message
675:"cql: Flat-file database query language"
349:. Common variants are CSV (delimiter is
326:
318:
204:
646:
256:Plain text files usually contain one
7:
69:adding citations to reliable sources
520:(a person's name, second column);
314:for improved search capabilities.
25:
636:(plain text database file format)
618:(standard Comma-Separated Values)
329:(each column has a fixed width).
317:Flat files are typically either
147:
45:
263:Examples of flat files include
56:needs additional citations for
1:
630:(classic flat-file processor)
624:(typical flat-file database)
323:comma-separated values (CSV)
209:Example of a flat file model
592:Database management system:
173:the claims made and adding
980:
597:database management system
355:tab-separated values (TSV)
339:delimiter-separated values
333:Delimiter-separated values
221:stored in a file called a
29:
654:Data Integration Glossary
429:1890 United States Census
30:Not to be confused with
928:Ordered Key-Value Store
659:March 20, 2009, at the
427:first exercised in the
819:Entity–attribute–value
709:10.1002/asi.4630200307
697:American Documentation
673:Fowler, Glenn (1994),
566:characters, such as a
476:Modern implementations
394:computational overhead
210:
959:Computer file formats
516:The columns include:
436:computer applications
208:
36:Flat file (hand tool)
438:were popular on the
410:declarative notation
400:Declarative notation
80:"Flat-file database"
65:improve this article
797:Entity–relationship
574:Relational algebra:
550:relational database
373:Fixed-width formats
319:delimiter-separated
582:relational algebra
556:Separated columns:
215:flat-file database
211:
158:possibly contains
18:Flat file database
941:
940:
886:Object–relational
881:Document-oriented
835:Multi-dimensional
480:Linear stores of
406:5apple|9pineapple
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202:
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160:original research
141:
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16:(Redirected from
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906:Transaction time
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501:Example database
465:and the popular
425:US Census Bureau
423:'s work for the
421:Herman Hollerith
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175:inline citations
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32:Flat file system
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964:Database models
954:Data management
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923:Key–value store
876:Column-oriented
864:Implementations
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814:Object-oriented
760:
758:Database models
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661:Wayback Machine
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448:word processors
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365:field. Several
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703:(3): 221–226.
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765:Common models
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491:address books
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156:This article
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82: –
81:
77:
76:Find sources:
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66:
60:
59:
54:This article
52:
48:
43:
42:
37:
33:
19:
870:
855:XML database
828:Other models
777:Hierarchical
771:
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591:
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568:tab or comma
555:
541:
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452:spreadsheets
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363:
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293:
289:Phone Number
288:
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247:
222:
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180:
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118:
108:
101:
94:
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75:
63:Please help
58:verification
55:
933:Triplestore
850:Star schema
782:Dimensional
622:Berkeley DB
610:/etc/passwd
586:field names
542:Data types:
327:fixed-width
308:text editor
304:spreadsheet
266:/etc/passwd
243:binary file
229:file (e.g.
948:Categories
901:Valid time
792:Relational
641:References
560:whitespace
296:typewriter
272:/etc/group
260:per line.
227:plain text
183:March 2015
167:improve it
121:March 2015
91:newspapers
891:Deductive
871:Flat file
717:1936-6108
564:delimiter
546:data type
526:unique ID
460:shareware
456:FileMaker
444:Macintosh
347:delimiter
321:(such as
277:Unix-like
223:flat file
171:verifying
896:Temporal
845:Semantic
802:Enhanced
657:Archived
634:Recfiles
604:See also
458:and the
442:and the
252:Overview
241:), or a
219:database
787:Network
552:system.
463:PC-File
416:History
369:exist.
341:files,
285:Address
165:Please
105:scholar
715:
580:under
484:data,
440:IBM PC
383:header
379:spaces
343:fields
312:online
287:, and
258:record
107:
100:
93:
86:
78:
840:Array
809:Graph
578:tuple
482:NoSQL
467:dBase
325:) or
217:is a
112:JSTOR
98:books
772:Flat
713:ISSN
522:team
518:name
507:data
486:JSON
450:and
302:. A
281:Name
269:and
84:news
705:doi
628:Awk
616:CSV
361:).
353:),
337:In
306:or
298:or
275:on
239:tsv
237:or
235:txt
231:csv
169:by
67:by
34:or
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701:20
699:.
695:.
677:,
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283:,
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190:(
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181:(
163:.
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128:(
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119:(
109:·
102:·
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61:.
38:.
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