Why Everyone’s Talking About PostgreSQL 18: The Biggest Update in Years

PostgreSQL 18 has arrived, and it’s being hailed as one of the most significant releases in the database’s history. Packed with developer-friendly features, this update delivers massive gains in performance, reliability, and security, solidifying PostgreSQL’s reputation as the “world’s most advanced open-source database.”

Here is a breakdown of the key features that make upgrading to PostgreSQL 18 a necessity for any serious application.

1. Performance and Query Optimization

PostgreSQL 18 brings groundbreaking changes to how data is read and how queries are planned, resulting in noticeable speed improvements for various workloads.

• Brand New Asynchronous I/O Subsystem [00:29]: This is one of the biggest wins in the new release. Instead of processing one disk read request at a time, PostgreSQL can now issue multiple requests in parallel on supported systems. This change can lead to up to three times faster reads in certain workloads.
• Smarter Query Planning with Skip Scans [00:44]: PostgreSQL 18 introduces Skip Scans for multi-column indexes. This means the query planner can now leverage an index even if your query doesn’t filter on the index’s first column, significantly reducing full table scans and improving query flexibility.
• Richer Query Debugging with EXPLAIN [02:08]: Understanding query performance is now much faster. The EXPLAIN keyword now shows buffer usage by default, providing richer statistics that help you quickly identify bottlenecks.

2. Maintenance and Painless Upgrades

Major version upgrades are smoother than ever, and new features help prevent common maintenance issues that can halt your database.

• Planner Statistics Carried Across Upgrades [01:09]: A perennial headache is fixed: your planner statistics will no longer reset during major version upgrades. This ensures your queries don’t slow down after an update while waiting for the system to analyze and rebuild everything.
• Faster and Smarter pg_upgrade [01:27]: The utility for moving between major versions is now faster, featuring better parallel checks and a new swap flag that minimizes downtime.
• Automatic Data Safety with Checksums [03:19]: New clusters now enable page checksums by default. This ensures data safety by helping to detect silent corruption in your database files without requiring extra setup.
• Aggressive Vacuuming for TxID Wraparound [03:27]: Vacuuming has been tuned to be more aggressive in freezing old tuples, drastically reducing the chance of a Transaction ID (TxID) wraparound issue—a catastrophic event that can bring a database to a halt.

3. Developer Quality of Life

Developers will benefit from cleaner schemas, better auditing, and more flexible data handling.

• Virtual Generated Columns by Default [01:34]: Generated columns now default to VIRTUAL, meaning they are calculated on read instead of being stored on disk. This saves storage space and keeps schemas significantly cleaner.
• OLD and NEW Keywords in RETURNING [01:50]: You can now use OLD and NEW keywords in the RETURNING clause of an UPDATE or DELETE statement. This allows you to instantly retrieve both the previous and new values of a row, which is perfect for auditing or logging purposes.

4. Security and Modern Authentication

PostgreSQL 18 moves toward modern security standards by embracing OAuth and deprecating outdated methods.

• OAuth 2.0 Authentication Support [02:16]: PostgreSQL 18 finally introduces native OAuth 2.0 authentication support, making it much easier to integrate with modern identity providers.
• MD5 Password Deprecation [02:25]: The older MD5 password method is now officially deprecated, driving users toward more secure options like SCRAM or external OAuth solutions.

5. Enhanced Replication for Large Systems

For those running large-scale or distributed systems, replication is now more reliable and easier to manage.

• Automatic Dropping of Idle Replication Slots [02:36]: A major issue in older versions was that idle replication slots could pile up and cause massive WAL (Write Ahead Log) growth, sometimes filling entire disks. PostgreSQL 18 can now automatically drop unused slots, preventing this runaway storage use.
• Parallel Streaming in Logical Replication [03:00]: Logical replication is now smarter; it reports conflicts when data can be applied and streams tables in parallel by default, ensuring faster and more transparent replication for large data sets.