The fourth beta for Postgres 15 was released on June 30, 2022 by the PostgreSQL Global Development Group. The beta signifies that no new features will be added to Postgres 15. This beta, future betas and release candidates will be made available by the PostgreSQL Global Development Group for testing before a production release later in the year, likely in October.
As always, EDB thanks everyone who has contributed to this great new release in any way! EDB is committed to helping the Community improve Postgres with each release, as it has done for the last 16 versions. For Postgres 15, EDB has made significant contributions in the following areas:
Developer productivity—MERGE SQL command
MERGE is a popular SQL standard command that can handle multiple INSERT, UPDATE and DELETEs in a single statement. Avoiding multiple PL/SQL statements simplifies SQL scripts for database developers and DBAs, as well as improving performance.
The Postgres implementation conforms to the SQL standard and, therefore, should also help transition database developers of both Microsoft SQL Server and Oracle Database to Postgres. Previously, MERGE statements needed to be entirely rewritten, perhaps using PostgreSQL INSERT... ON CONFLICT UPDATE syntax. EDB had previously seen customers who used the MERGE clause so extensively that rewriting was expensive enough to derail migrating to Postgres from commercial databases, so this is an important new capability.
EDB continues to work with the PostgreSQL community applying the least privilege principle and reducing the number of tasks requiring operators with superuser privileges. Postgres 15 allows granting SET and ALTER SYSTEM privileges on individual configuration basis, for example, creating a role with privileges to set GUCs related to system maintenance that could previously be changed only by superusers.
Also, logical replication now allows non-superusers to be logical replication subscription owners, greatly improving security. The restriction that only a superuser can create a subscription still applies. But now, starting with Postgres 15, ownership of the subscription can be transferred to a low privilege user before enabling that subscription. In practice, this database user would be one who cannot insert, update, delete, truncate or copy to tables that you do not intend to be modified. Protections are also built in to protect subscription owners from circumventing row-level security policies.
Improvements to database security continue to be a major theme for EDB, with major enhancements coming to EDB’s commercial Postgres database in February 2023, along with working with the Postgres community on significant security advances in PostgreSQL 16.
Backup and recovery
Postgres 15 adds server-side backup compression, providing new options for taking backups quickly and efficiently. The amount of data that needs to be transferred over the network can be reduced by compressing the backup files on the server side. Along with gzip, Zstandard and LZ4 compression types are available to support multiple use cases:
- Zstandard with multiple threads when spare CPU is available and both a strong compression ratio and fast compression time is desired,
- LZ4 when only a single thread can be spared, and compression speed is more important than compression ratio.
Whether it is speeding up network transfers from the backup server to remote storage, lowering the time spent compressing backups or reducing your Postgres backups' storage footprint, Postgres 15 has new options to help you out.
EDB plans to continue working with the PostgreSQL community to improve backup and recovery options in core Postgres and expects more big enhancements in this area for v16 in 2023.
EDB continues its long history of contribution to the Open Source PostgreSQL community to merge many advanced logical replication capabilities first introduced in EDB Postgres Distributed upstream into PostgreSQL. EDB contributed significantly to selective replication through column and row filtering, allowing for advanced logical replication use cases and reducing network traffic between the publication and subscriber nodes. EDB also contributed significantly to allowing the skipping of transactions on a subscriber using ALTER SUBSCRIPTION…SKIP, another capability derived from EDB Postgres Distributed.
Logical replication will continue to be an investment area for EDB, with significant improvements in EDB Postgres Distributed 5 coming in Winter 2022 and EDB developers working with the community to merge many logical replication enhancements into PostgreSQL over the coming releases.
EDB staff have also contributed to several miscellaneous enhancements to Postgres 15, which improve performance, usability and diagnostics.