File Layout

File Layout - This specifies the exact content of fields in a database, including length and name. The layout needs to be predetermined for processing purposes.

[Category=Database Management ]

CNM, 05 November 2009 11:02:34, http://www.cnm.co.uk/glossary-of-terms.html

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File Layout - The sequence of data fields for a particular record stored on magnetic media. For example: First and last name, Primary address, Secondary address, phone number, date of last purchase, amount of last purchase. In a Fixed-Field file, each of those data elements, or fields, will always occupy the same number of bytes on each records, whether or not any data resides in those fields. In a Variable-Length file, the length of each data element and each individual record depends entirely upon the length of the "live" data in that field. For example, a fixed-field file will always have the name field take up a specific number of bytes, say positions 1 to 30. In a variable-length file, if the first and last names (and the space in between them!) add up to 22 characters, or bytes, that is how long the name field is in that record. You can immediately see two consequences immediately: Variable-length-field files take up less space on a tape or diskette, but they can be a nightmare to decode, read or process, because the data is never in a consistent position for each record!

[Category=Database Marketing ]

Source: Postcom, 05 March 2010 09:51:23, http://postcom.org/public/admail_image/glossary.htm