Neues vom PostgreSQL Planet

Parallel scans need a minimum table or index size to be considered—but that minimum also sets the bottom rung of the ladder the planner climbs to decide how…

PgBouncer 1.26.0 patches three CVEs, two triggerable without authentication.

What is Direct I/O, and why would a managed Postgres care about it when taking a backup? Every day, a backup copies your whole database, hundreds of gigabytes, off the same NVMe drives that are answering your queries, and ships it to object storage. Linux treats those reads like any other file read: it keeps a copy of every byte in memory, in the page cache, in case someone asks for it again. Nobody will. To make room for those copies, the kernel throws out data Postgres had in memory and was about to use, and the next query that needs it goes to disk instead.

PostgreSQL 18 added md5_password_warnings to suppress deprecation notices about MD5 passwords—but it only warns when setting them, not when using them.

In this post, I walk through integrating JFrog Artifactory with Fujitsu Enterprise Postgres and using Transparent Data Encryption to encrypt the Artifactory metadata stored in the database.

Last week we had our September PostgresEDI meetup, the first since postgres.scot went up as the home for Postgres events in Scotland.

Two BM25 optimizations and benchmark configuration changes inspired by PlanetScale's TIN benchmarks make ParadeDB's text search faster without changing its document identifiers.

Over the past month, several major features got reverted from Postgres 19. At this point, even if everything else goes perfectly, Postgres 19 will be released about a month later than originally planned. A couple recent blog posts seem to suggest the reverts happened due to AI finding complex bugs in those patches, with fixes way too invasive this late in the development cycle. I don’t think that narrative matches reality, and I think it matters to correct that.

Unique constraints in multi-tenant PostgreSQL 17, tested: per tenant or global, soft delete, case, NULLs, ON CONFLICT, and what a duplicate-key error reveals.

Deleting one tenant from a shared PostgreSQL 17 database, measured: cascade, batches or dropping a partition; locks, batch size, disk space, what stays behind.

count(*) per tenant in PostgreSQL 17, measured: why it got 5× slower for the largest tenant, when estimates are wrong, and what a counter row costs under load.

A trigger-based audit log in PostgreSQL 17, measured: row against statement triggers, full rows against changed columns, and row-level security on the log.

One tenant queues 1,000 jobs, ten others five each: FIFO against round-robin with SKIP LOCKED in PostgreSQL 17, measured, plus a 10-second planner trap.

What an RLS policy costs in PostgreSQL 17: function volatility, the (select …) wrapper, membership subqueries and the leakproof rule that disables your index.

RLS behind PgBouncer in transaction mode, measured: which tenant context leaks, what SET LOCAL does outside a transaction, and one plan shared by tenants.

Query hints: You asked for it, Postgres 19 gave it to you. Now, they are just waiting to see how you use it.

For years the Postgres community was against adding support for hints. They felt if you had correctly analyzed tables, the Postgres query planner would make the right choice. And they're not wrong, for the most part. Yet many DBAs and developers will tell you of a time when a plan suddenly changed or something was saved by a hint. We can debate the good and bad elements of hints, but the cool thing is that you will soon have a choice in Postgres 19+.

Out now on GitHub and PGXN, pg_clickhouse v0.11.0 and the chdb extension v0.1.2 continue our dogged focus on cross-database compatibility. A slew of these enhancements derive from our header-only C libraries, clickhouse-c and pg-clickhouse-c. Let's take a look at just three of the changes in these releases.

What a character {#what_a_character}

`max_wal_size` is a checkpoint trigger, not a maximum—and the real cost is paid by setting it too low, not too high.

This is my personal experiment, not an official Apache Cloudberry release.

Since 2017 I have been keeping an eye on the PostgreSQL ecosystem for analytics and data warehousing. At work I had used AWS Redshift, with all the drawbacks and inconveniences a developer gets from a fork of an old PostgreSQL. To my mind, the ideal PostgreSQL-based solution should run on the latest PostgreSQL release, be built as an extension, be easy to start locally in a container for tests, and work with the latest versions of existing extensions such as PostGIS and pgvector.

After trying not to add any Rust packages to the PostgreSQL RPM repository, I finally bit the bullet and pushed pgrx and postgresql_anonymizer to the RPM repos, along with packaging guidelines:

https://github.com/pgdg-packaging/pgdg-rpms/wiki/Packaging-Rust-extensions-(pgrx

Some limitations exist for now:

https://github.com/pgdg-packaging/pgdg-rpms/wiki/Packaging-Rust-extensions-(pgrx)#supported-distributions

Hoping to add RHEL 10.3 and 9.9 support in November.

Enjoy!