- 08 Nov, 2025
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- 3 Mins Read
How PostgreSQL Handles Concurrency and Locks
Introduction
Concurrency is one of the most powerful features of PostgreSQL — allowing multiple users to access and modify data simultaneously without conflicts. In this article, we’ll explore how PostgreSQL handles concurrency and locks, ensuring data integrity in multi-user environments.
If you’re looking to learn PostgreSQL online or upgrade your database management skills, understanding this concept is essential.
1. Understanding Concurrency in PostgreSQL
Concurrency refers to multiple database sessions performing read and write operations at the same time. PostgreSQL uses an advanced system called MVCC (Multi-Version Concurrency Control) to manage this.
Instead of blocking readers and writers, MVCC creates snapshots of data, allowing:
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Readers to access data as it was at the start of the transaction.
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Writers to modify data without waiting for readers to finish.
This makes PostgreSQL extremely efficient for high-performance environments and is a key topic in any Postgres database training course.
2. Types of Locks in PostgreSQL
While MVCC minimizes locking, PostgreSQL still uses locks to maintain consistency when needed. Here are the main types:
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Row-Level Locks: Used during updates or deletes to prevent other transactions from modifying the same row.
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Table-Level Locks: Applied when structural changes occur (like
ALTER TABLE). -
Advisory Locks: User-defined locks that help developers manage complex concurrency control logic.
Knowing how these locks work is essential when you learn PostgreSQL online or manage live production databases.
3. MVCC: The Secret Behind Smooth Concurrency
PostgreSQL’s MVCC ensures that:
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Each transaction gets its own snapshot of the database.
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Readers never block writers, and writers never block readers.
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Old versions of rows (called tuples) are cleaned up later using the VACUUM process.
This system provides ACID compliance and ensures your database remains consistent under heavy load.
4. Deadlocks and How to Avoid Them
Even with MVCC, deadlocks can happen when transactions hold locks that each other need.
To avoid deadlocks:
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Always access tables in the same order across transactions.
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Keep transactions short.
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Use explicit locking only when necessary.
Deadlock management is a crucial skill taught in professional Postgres database training programs.
5. Monitoring Locks in PostgreSQL
You can easily monitor active locks using:
This command helps database administrators identify blocked queries and take corrective action.
When you learn PostgreSQL online, practicing with such real-world queries helps you gain hands-on experience.
Conclusion
Archive Mode in PostgreSQL is more than just a backup feature — it’s the foundation of a reliable recovery strategy. Whether you’re learning through a PostgreSQL Course, practicing via a PostgreSQL Learn Online module, or advancing your skills to Learn PostgreSQL DBA, mastering this configuration ensures your data remains safe, consistent, and recoverable at all times.
Continuous learning and hands-on implementation are key to becoming a confident PostgreSQL professional.
At Learnomate Technologies, we make sure you not only understand such cutting-edge features but also know how to implement them in real-world projects. Whether you’re a beginner looking to break into the database world or an experienced professional upgrading your skillset—we’ve got your back with the most practical, hands-on training in Oracle technologies.
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