Liquibase vs PostgreSQL: What are the differences?

Introduction: Liquibase is an open-source database-independent change management tool, whereas PostgreSQL is an open-source relational database management system (RDBMS). While Liquibase is used to manage and track changes made to the database schema, PostgreSQL is the actual database engine that stores and retrieves data.

1. Version Control: One key difference between Liquibase and PostgreSQL is that Liquibase provides built-in version control capabilities for database schema, making it easy to manage and track changes over time. On the other hand, PostgreSQL does not have built-in version control features, so developers have to rely on external tools or manual processes to track and manage schema changes.

2. Cross-Platform Compatibility: Liquibase is designed to be database-agnostic, which means it can be used with various database systems, including PostgreSQL. It provides a consistent way to manage schema changes regardless of the underlying database engine. In contrast, PostgreSQL is a specific RDBMS and is not compatible with other database systems out of the box. It is optimized for running on PostgreSQL server instances only.

3. Data Manipulation Language (DML): Liquibase focuses primarily on managing database schema changes, such as adding or modifying tables, columns, and constraints. It does not provide extensive support for writing complex data manipulation queries or stored procedures. PostgreSQL, on the other hand, offers a powerful and comprehensive DML language, including SQL, procedural languages like PL/pgSQL, and a vast array of built-in functions for data manipulation.

4. Concurrency and Isolation: Liquibase is a single-threaded tool used primarily during development and deployment processes. It does not handle concurrent transactions or provide isolation mechanisms for handling concurrent access to the database. PostgreSQL, being a fully-fledged RDBMS, offers multi-user concurrency control and various isolation levels to handle concurrent transactions effectively.

5. Performance and Scalability: Liquibase is not designed to handle high-volume or high-concurrency workloads efficiently. It is meant to be used as a development and deployment tool. On the other hand, PostgreSQL is optimized for performance and scalability, capable of handling large and complex databases with millions of transactions per second.

6. Expensive Operations: Liquibase does not have built-in mechanisms to handle expensive operations like index rebuilding, table partitioning, or advanced query optimization. These operations need to be handled separately outside of Liquibase. In comparison, PostgreSQL provides tools and optimization techniques to handle these expensive operations efficiently, ensuring the database performs at its best.

In Summary, Liquibase provides version control, cross-platform compatibility, and schema change management, while PostgreSQL offers advanced data manipulation capabilities, concurrency control, performance, scalability, and tools for handling expensive operations on the database.