PostgreSQL 18 Beta 1 Available for Testing

The PostgreSQL Global Development Group has announced the availability of PostgreSQL 18 Beta 1, the first preview release of the next major version. Beta releases are intended for testing — not for production use.

What’s new in PostgreSQL 18

OAuth 2.0 / OAUTHBEARER authentication

PostgreSQL 18 introduces native support for OAuth 2.0 authentication via the OAUTHBEARER SASL mechanism. This allows PostgreSQL to integrate directly with identity providers such as Okta, Azure AD, and Keycloak without an external proxy. The feature is configurable per-database and per-role in pg_hba.conf.

Incremental backup enhancements

Building on the incremental backup infrastructure introduced in PostgreSQL 17, version 18 adds support for backup manifests that reference multiple prior backups in a chain, reducing the restore time for long-lived backup strategies. The pg_combinebackup utility has been extended to handle multi-level chains.

Connection slot management

The longstanding “sorry, too many clients” error is now more manageable. PostgreSQL 18 introduces a reserved connection pool for superusers and replication connections that is separate from the general max_connections limit, eliminating the risk of administrative lock-out under connection pressure.

Other improvements

• EXPLAIN output now includes buffer usage for each plan node by default
• pg_stat_io gains fsync and fdatasync counters
• Logical replication now supports two-phase commit for subscribers
• COPY FROM now supports ON_ERROR IGNORE to skip malformed rows
• Improved vacuum parallelism for large tables with many dead tuples

How to test

Beta packages are available for major Linux distributions and macOS via the PostgreSQL APT and Yum repositories. A Docker image is also available on Docker Hub under postgres:18-beta1.

Report bugs and regression findings via the pgsql-bugs mailing list.