Embedded DBMS

Refers to a DBMS tightly integrated with an application. Operates inside the application and is usually invisible to the user.

Used in: mobile apps, IoT systems, industrial devices, and embedded controllers.

Characteristics

• Hidden from end-user.
• Minimal or no maintenance.
• No dedicated Database Administrator (DBA).
• Supports in-memory or on-disk modes.
• Fast access, local within the application.
• Low total cost of ownership (TCO).

Design Concerns

• APIs
  SQL, native, or proprietary interfaces.
• Architectures
  Lightly or deeply embedded.
• Storage modes
  In-memory, on-disk, or hybrid.
• Database types
  Relational, object-oriented, key-value, or EAV models.
• Target markets
  Mobile, real-time, or resource-limited devices.

Characteristics

• Integrated into host applications.
• Often embedded through scripting (e.g., Python, Java).
• Lightweight and low-cost.
• May not scale well for large systems.
• Transaction control is supported.
• Limited text search or SQL support.

Architectures

Client–Server Architecture

The traditional one. Database server is a separate process. Clients connect via network (JDBC, ODBC, etc.). Multiple clients can access simultaneously. Requires installation, setup, and maintenance.

Lightly Embedded Architecture

Database engine installed with the application. Resides on the same machine. Small footprint, nearly full features. Can be accessed by multiple apps.

Deeply Embedded Architecture

Database runs inside the application process. No external database engine. Distributed easily as a library file. Popular in mobile apps. Ideal for offline and single-user environments.

Examples