The Misconception of Relational Database and the ACID Properties

Relational Database Model is the database model which is widely used and has been used for decades. It is precisely described based on the mathematical concept of relation. The abstract concept is presented by the tabular format, commonly known as the SQL tables. Due to the simplicity of the tabular format and the simple, high productivity SQL language, software developers without or with minimum theoretical backgrounds can use RDBMSs for application development. There are also DBMSs which are based on other database models which do not use the SQL language and are collectively called NoSQL databases. These systems' advocates claim that the Relational Database Model and RDBMSs require ACID transactions. This paper clarifies the related terms and concepts of the Relational Database Model. The more recent concept of relation variable is explained and related to SQL tables. ACID properties of transactions are also presented to confirm that they are not directly related to a particular database model. Thus, it is a misconception that the Relational Database Model requires ACID properties.