Semi-structured data
Encyclopedia
Semi-structured data is a form of structured data that does not conform with the formal structure of tables and data models associated with relational database
s but nonetheless contains tags or other markers to separate semantic elements and enforce hierarchies of records and fields within the data. Therefore, it is also known as schemaless or self-describing structure.
In the semi-structured data, the entities belongs to the same class may have different attributes even though they are grouped together, and the attributes order is not important.
Semi-structured data is increasingly occurring since the advent of the Internet
where full-text documents and databases are not the only forms of data any more and different applications need a medium for exchanging information. Especially in object-oriented databases, you often find semi-structured data.
, other markup languages, email
, and EDI
are all forms of semi-structured data. OEM
(Object Exchange Model) was created prior to XML as a means of self-describing a data structure.
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
s but nonetheless contains tags or other markers to separate semantic elements and enforce hierarchies of records and fields within the data. Therefore, it is also known as schemaless or self-describing structure.
In the semi-structured data, the entities belongs to the same class may have different attributes even though they are grouped together, and the attributes order is not important.
Semi-structured data is increasingly occurring since the advent of the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
where full-text documents and databases are not the only forms of data any more and different applications need a medium for exchanging information. Especially in object-oriented databases, you often find semi-structured data.
Types of Semi-structured data
XMLXML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
, other markup languages, email
Email
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
, and EDI
Electronic Data Interchange
Electronic data interchange is the structured transmission of data between organizations by electronic means. It is used to transfer electronic documents or business data from one computer system to another computer system, i.e...
are all forms of semi-structured data. OEM
Object Exchange Model
The Object Exchange Model is a model for exchanging semi-structured data between object-oriented databases. It serves as the basic Data model in numerous projects of the Stanford University Database Group, including Tsimmis, Lore, and C3 ....
(Object Exchange Model) was created prior to XML as a means of self-describing a data structure.