Properties of RDBMSs and NoSQL databases
Last updated on: 2019-11-19
Authored by: Satyakam Mishra
This page presents the characteristics of relational database management systems (RDBMSs) and NoSQL databases.
Prerequisite
For an introduction to relational databases and NoSQL databases, see Types of databases.
Properties of relational databases
Relational databases are efficient systems, which makes them a common choice for storing financial records, logistical information, personnel data, and other information in new databases. Because they are easier to understand and use than NoSQL databases, relational databases also frequently replace legacy hierarchical databases and network databases.
Relational databases have the following properties:
- Values are atomic.
- All of the values in a column have the same data type.
- Each row is unique.
- The sequence of columns is insignificant.
- The sequence of rows is insignificant.
- Each column has a unique name.
- Integrity constraints maintain data consistency across multiple tables.
Properties of NoSQL databases
NoSQL is a schema-less alternative to SQL and RDBMSs designed to store, process, and analyze extremely large amounts of unstructured data.
In NoSQL databases, the principles of ACID (atomicity, consistency, isolation, and durability) are reduced. In addition, the process of normalization is not mandatory in NoSQL. Due to the size and speed of modern data, it is preferable for NoSQL databases to be de-normalized.
NoSQL databases have the following properties:
- They have higher scalability.
- They use distributed computing.
- They are cost effective.
- They support flexible schema.
- They’re able to process both unstructured and semi-structured data.
- There are no complex relationships, such as the ones between tables in an RDBMS.
The following table shows the types of non-relational databases and the features associated with them:
| Type | Performance | Scalability | Flexibility | Complexity |
|---|---|---|---|---|
| Key-value store | High | High | High | High |
| Column store | High | High | Moderate | Low |
| Document store | High | Variable to high | High | Low |
| Graph-based | Variable | Variable | High | High |
Next step
Reasons to use an SQL database
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