What is a Flat File?
Flat files present complex hierarchical structural data in a record–based storage format. Unlike XML, flat files do not embed structural data (metadata) within the data. The data in the flat file has been “flattened” by removing the hierarchical relationship between records, leaving the records intact as a single logical record of application data.
All flat files consist of a list of records containing fields and composites:
Fields are atomic pieces of data (for example, ID and ID qualifier, Date and time).
Composites contain multiple fields (for example, ID and ID qualifier, Date and time). The fields within a composite are referred to as
subfields.
Records (also known as segments) are sequences of fields and/or composites.
For example, the following flat file data and its list of delimiters enables you to see how elements (records, composites, and fields) within a flat file can be identified.
To communicate using flat files, you must create a flat file schema that contains a particular flat file’s structural information, including how to identify records and separate those records into fields.
The flat file schema enables receivers of flat file documents to parse and validate inbound flat files for use by their back–end systems. The flat file schema also enables senders of documents to convert outbound documents to flat file format. Once converted to flat file format, the files can be delivered to another back–end system.
