A majority of medium-sized and large businesses rely on data to make decisions every day. It’s essential to most business processes, from understanding the customers’ behavior to making smart marketing choices. While authenticity and consistency of information are increasingly important, developers have to deal with unstructured data and relationships between its elements that are fluid and not easy to define.

To make sense of the vast amounts of varied information, businesses and organizations turn to popular data modeling tools. The specialized data modeling  software helps discover the exact nature of the information they control, the relationships between data sets, and how they can best use the asset. This article highlights some of the popular free data modeling tools which might come in handy for designing your database.

open source data modeling tools


Design of Information Systems

Before looking at the best data modeling tools, let's break down the process. The flow and relationships of the data need to be defined and structured for optimal results. That’s the purpose of creating data models. A model for an information system defines data elements, the structure, and relationships between the elements. It helps analyze the requirements that are essential for supporting the business processes. It assists in the visual representation of data and enforces business rules, regulatory compliances, and government policies on the information.


The process starts with collecting and analyzing data-related and functional requirements. After that, three data models are produced before an actual database can be built:


1. Conceptual design:

With the help of the database modeling software, business stakeholders and data architects record the initial data requirements as a conceptual data model which defines what the system contains. It establishes the entities (real-world things), their attributes (characteristics or properties), and relationships (dependencies or associations between the entities). The resulting Unified Modelling Language (UML) class or Entity Relationship Diagrams (ERD) rarely contain any details of the actual database structures.


2. Logical design:

Typically, it’s data architects and business analysts who convert the conceptual design into one or multiple logical data models. Each one documents the structure of the data elements, sets the relationships between them, and defines how the system should be implemented regardless of a database management system (DBMS). The concepts of primary keys and foreign keys come into play at this phase.


3. Physical design:

The logical design is transformed into a physical layout of the database. Database administrators (DBAs) and developers typically create it. A complete physical data design should include all the DB columns keys, indexes, triggers, constraint definitions, linking tables, partitioned tables, and clusters. As it describes how the system will be implemented, it’s important to know which DBMS is to be used: the choice will influence disk requirements, security requirements, and other aspects of the model. It helps visualize the DB structure and generate the schema, creates accounts for access, performance, and specific storage allocation details, and adds the data to be stored. It helps analysts calculate storage estimates.

open source data modeling tools

Image taken from Visual Paradigm User's Guide


Such models facilitate consistency in naming conventions, default values, semantics, and security, simultaneously ensuring the quality of the data. They help promote communication within and across organizations.


All-powerful data modeling tools are meant to simplify and speed up the creation of DB designs and to minimize human errors. The software helps with creating data description language (DDL), generating reports that can be helpful for the stakeholders, and increases your chances to create a high-performance DB. Good design lessens the maintenance efforts, decreases probability of failures, provides a mechanism for communication between the users, and generally saves their time and efforts to perform a task.


Focusing on free database design software available in the market, below we’ve listed some widely used tools along with the reasons for their popularity. For your convenience, we’ll start with open-source data modeling tools. 


Open Source Data Modeling Tools for Enterprise


Archi is a free cross-platform visual modeling and design tool for work with the ArchiMate enterprise architecture modeling language. Used to create ArchiMate models and sketches, the tool fulfills the needs of ArchiMate beginners, pros, and associated stakeholders. It’s utilized globally by banks, insurance companies, industry, EA consultants, educational organizations, and universities.


Database Deployment Manager

DDM is a desktop-oriented multi-platform database design tool. DBAs use it to create database structures which are then deployed into an existing one. DDM is distributed as free data modeling software under the LGPL License.


This tool allows users to create data types which can be used to develop tables, manage database views and tables, load/save startup for tables from CSV files, validate design, and browse an existing DB and import tables into the solution. Its DBM application provides an easy way of creating the initial database layout and has a unique object-oriented modeling feature, Visual Query Builder, and ERD generation. DDM also has an SQL script generator for a target DB engine and parallel deployment into chosen databases. 


Other Free Data Modeling Tools


This web-based tool for database design is used for documenting a complex DB design in a simple, interactive diagram. The commercial product is targeting businesses, but it’s possible to get started with a full-value free plan.


The software for data modeling offers smart visualization features for designing the DB structure while visualizing tables with keys, indexes, relationships, etc. It supports forward and reverse engineering, i.e. going from a logical data model to a physical, and vice versa. It’s packed with intuitive tools like template projects, fast search, and naming conventions, and helps identify potential errors before you write any code.


One can create a project with Microsoft SQL Server, Oracle, MySQL or SQLite, and change the database at any time with automatically built-in data type mappings. The project is documented automatically, allowing to keep track throughout project versioning and simplifying the learning process for the team members.


 ERBuilder Data Modeler

The software modeling database is suitable for both beginners and experts. It lets database engineers design DBs graphically by using ERDs and physical designs to generate popular SQL DBs. Visualized structures help them understand existing DBs, create new ones, and modify, analyze, and optimize solutions. A sophisticated visual data modeling environment helps deploy the databases. The software reduces errors in development and improves productivity. 


ER/Builder facilitates the creation of index, keys, triggers, stored procedures, views, generators, and domains. Other useful features include, but are not limited to, DBMS-specific data models, object browser (treeview), DDL script generation, and reverse engineering for MySQL, PostgreSQL, and Firebird.


 Oracle SQL Developer Data Modeler

open source data modeling tools

The data modeling tool for Oracle enhances productivity and simplifies the creation, browsing, and editing of various designs. Oracle SQL Developer Data Modeler provides forward and reverse engineering capabilities and supports collaborative development through integrated source code control. It can be used in both traditional and cloud environments.


SQL Database Modeler

This software for modeling data allows designing your database on any browser, without any extra database modeling tools/apps or engines. A friendly user interface, the ability to create multiple subject areas, project sharing, and other features facilitate the work. Because SqlDBM is in beta version, it’s free to use.


SqlDBM can be used to design and manage large and small DBs. If there’s a database but no ERD or physical design, you can use reverse engineering to export your database schema as an SQL script, and then run these scripts in MSSQL Studio or SQL Server Developer Tools to generate the XML database-creation scripts. After that, upload the XML statements into SqlDBM and create your physical design or ERD.


To Recap

Data management is essential to any business’ growth strategy nowadays. With the new generation of open source DBs, developers don’t need to define the data model upfront and can update files in the application without interruption or downtime. Best data modeling tools promote flexible database schema design and a modern iterative approach. These tools enable organizations to incorporate, process, and analyze emerging types of data and future-proof their applications.


This post listed some of the popular instruments which simplify the process by bolstering useful features. Apart from these, there are many more, so everyone can find their perfect commercial or free data modeling tool. Among paid instruments, the first to mention are usually DeZign for Databases, ER/Studio Data Architect, IBM System Architect, Lucidсhart, SAP PowerDesigner, Vertabelo, Visual Paradigm ERD Tool, and so on. Another table comparing the tools is available here.




What are Data Modeling tools used for?

They help you create database structures with a simple and visually appealing data model—a roadmap for how your product will organize and manage that data.


What are the 5 data modeling techniques?

There are core 5 data modeling techniques: hierarchical, network, relational  entity-relationship, and object-oriented data model.


Which data model is mostly used today?

It is generally accepted that the most popular model today is the Relational model.

Written by:
Denis  Sheremetov
Denis Sheremetov

CTO at Onix-Systems

Development of custom solutions for all sizes of businesses. Ensuring efficient and secure technology use.

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Mila  Slesar
Mila Slesar