Structured vs. Semi-Structured Data

Structured data

As in relational databases: Entities/tuples with the same attributes are within the same classes/tables .

Schema forces strict-structure: Attributes in entities must be

  1. present
  1. of the same order
  1. of the same data type (ie. string, integer, date, …)

Semi-structured data

Only entities and classes .

No schema → rules above dont apply.

Useful for ie. data on the web.

Labled trees

a self describing data model: schema is contained within the data

Examples for formalisms

Object Exchange Model (OEM)

JavaScript Object Notation (JSON)

eXtensible Markup Language (XML)