What’s New in PostgreSQL 15? Performance Boosts, New SQL Features, and Enhanced Replication

On October 13 2022, the PostgreSQL global development team announced PostgreSQL 15, the latest release of the world’s most advanced open‑source relational database.

Built on recent performance improvements, PostgreSQL 15 delivers significant gains for both local and distributed workloads, notably faster in‑memory and on‑disk sorting that can be 25 %–400 % quicker depending on data type, parallel execution of SELECT DISTINCT, and enhanced window‑function performance for row_number(), rank(), dense_rank(), and count().

The release adds asynchronous commit support to the foreign‑data wrapper postgres_fdw, enabling asynchronous remote queries.

WAL handling is improved with optional compression using LZ4 or Zstandard, prefetch support for pages referenced in WAL, and server‑side compression options (gzip, LZ4, ZSTD) for pg_basebackup. Custom modules can now be used for archiving, eliminating the need for external shell commands.

SQL enhancements include the standard MERGE command, which combines INSERT, UPDATE, and DELETE logic in a single statement, and new regular‑expression functions regexp_count(), regexp_instr(), regexp_like(), and regexp_substr(). The multirange data type is also supported via the range_agg aggregate.

Security is strengthened with the security_invoker option, allowing views to run with the caller’s privileges rather than the view creator’s, adding an extra protection layer.

Logical replication receives more flexibility: publishers can define row filters and column lists, users can skip replay‑conflict transactions, subscriptions can be automatically disabled on error, and two‑phase commit (2PC) can be combined with logical replication.

Logging now offers a new jsonlog format that outputs logs as structured JSON, facilitating integration with modern log‑processing systems.

Configuration management is enhanced; administrators can grant users permission to change server‑level parameters, and a new meta‑command \dconfig in psql allows searching configuration details.

Server‑level statistics are collected in shared memory, removing the need for a separate statistics collector process. ICU collation rules can now be set as the default for a cluster or individual database.

A built‑in extension walinspec lets users inspect WAL file contents directly from SQL.

The default CREATE privilege on the public schema is revoked for all users except the database owner, tightening security.

Deprecated features are removed: the long‑standing “exclusive backup” mode in PL/Python and support for Python 2 have been dropped.