Open-Source DBMS — Identify the Correct Definition Which statement best describes an open-source database management system (DBMS) in practical, industry terms?

Introduction / Context:
Open-source DBMS platforms such as PostgreSQL, MySQL, and MariaDB are widely used in startups and enterprises. Understanding what “open-source” actually means helps learners separate licensing, cost, and transparency considerations from unrelated performance or compliance myths.

Given Data / Assumptions:

• The question asks for the accurate characterization of an open-source DBMS.
• Open-source typically relates to access to source code under an OSI-approved license.
• “Free or nearly free” reflects that binaries are often free of charge, while paid support may exist.

Concept / Approach:
Open-source software grants users rights to view, modify, and redistribute source code under the terms of a permissive or copyleft license. For DBMSs, this means transparency in implementation, community-driven improvements, and ecosystem tooling. Cost is usually zero for the software itself, though organizations may purchase support, tooling, or cloud services. SQL compliance varies by product but is unrelated to the open-source nature itself.

Step-by-Step Solution:
1) Identify the defining property: public availability of source code under an open license.2) Recognize typical pricing: free to download and use; optional paid support.3) Separate competitiveness and SQL compliance from licensing; these are product-specific, not inherent to open-source.4) Select the option that emphasizes public source availability and low/no cost.

Verification / Alternative check:
Review OSI definitions and licenses (for example, PostgreSQL License, GPL, LGPL). These confirm rights to source access and redistribution, which align with the open-source model.

Why Other Options Are Wrong:

• B: Contradicts the essence of open-source; source must be available.
• C/D: Tie competitiveness or SQL compliance to licensing; these are independent dimensions.
• E: Describes proprietary software, not open-source.

Common Pitfalls:
Equating “free” with “open-source.” Some freeware is not open-source; conversely, open-source can have paid distributions or support.

Final Answer:
Is free or nearly free database software whose source code is publicly available