Neues vom PostgreSQL Planet

New year, new job.

I’m pleased to announce that I started a new job on January 2 at Tembo, a fully-managed PostgreSQL developer platform. Tembo blogged the news, too.

On 4th of January 2024, Tom Lane committed patch: In plpgsql, allow %TYPE and %ROWTYPE to be followed by array decoration.   This provides the useful ability to declare a variable that is an array of the type of some other variable or some table column.

Need to extract a specific substring out of a text in PostgreSQL®? Read here how!

PostgreSQL SUBSTRING allows you to extract a particular string out of a text column.

The text column can be of:

Discover the reasons behind a planner's selection of Hash aggregate and Hash joins for data processing and understand their workings through this blog.

The post Understanding Hash aggregates and Hash Joins in PostgreSQL appeared first on Stormatics.

On the Customer Success Engineering team at Crunchy Bridge, we run across customers with lock issues on their Postgres database from time to time. Locks can have a cascading effect on queries. If one process is locking a table, then a query can be waiting on the process before it, and the process before that one. Major lock issues can quickly take down an entire production Postgres instance or application.

Last week the good old Gunnar Morling launched an interesting challenge about ordering 1 billion rows in Java.

© Laurenz Albe 2024

I recently investigated a surprising behavior of the DBeaver database client in connection with PostgreSQL parallel query, which I’d like to share with you. This might be interesting for everybody who accesses PostgreSQL using the JDBC driver.

While counting is common in every application, sometimes it is not enough: when we need to display the amount of unique users generating traffic in our website or provide the number of disparate items included in an order we need to apply a distinct count.

In my role as a Solutions Architect at Crunchy Data, I help customers get up and running with Crunchy Postgres for Kubernetes (CPK). Installing and managing a Postgres cluster in Kubernetes has never been easier. However, sometimes things don't go as planned and I’ve noticed a few major areas where Kubernetes installations go awry.

A brief history of logical replication in Postgres — and looking ahead at its likely future evolution This blog is divided into two parts. In this section, we walk through how the logical replication feature has evolved over the years, what the recent improvements for Postgres logical replication are, and how the feature will likely change in the future.

This is a short announcement of a new PostgreSQL wiki page called Operations cheat sheet . I curated many useful pages (that I find so), mostly from blogs registered in Planet PostgreSQL . Also, I summarized some topics for quick reference. I created this page so that users can learn from rich wisdom PostgreSQL community people and get ready for troubleshooting. For details, please see the Introduction section.

Vector search in Postgres is a space that has seen very active development in the last few months. While Pgvector is known to most people, a few weeks ago we came across Lantern, which also builds a Postgres-based vector database. So, we thought about benchmarking both to compare the two approaches. In this post, we'll cover:

A short recap on some issues when dealing with PL/Java and Rocky Linux.

Installing PL/Java on PostgreSQL 16 and Rocky Linux

It has been a while since I last used PL/Java, and that’s mostly due to the fact that I (luckily) use much more Perl (and hence, PL/Perl) in my everyday activity than Java.

In PostgreSQL, functions and procedures can be written in many different programming languages including but not limited to PL/pgSQL, PL/Perl, PL/Python and a lot more. This flexibility gives the end user the choice to write code in languages of their choice. However, this flexibility has some implications which are often forgotten. Loading libraries early is one of them.

• Background
• Password Encryption (i.e.

Introduction

In this blog, we’ll go over PostgreSQL’s implementation and handling of JSON objects. Having some experience with Linux, Postgres, and JSON is necessary as we’ll not only be going over these new features but also how to implement them. This blog was written using PostgreSQL 16 (Development Version) running on Ubuntu 23.04. First I’ll go over some background on JSON as a short refresher, then move on to how we use JSON in Postgres, followed by what helpful functions we can use to interact with JSON objects.

On 4th of January 2024, Peter Eisentraut committed patch: ALTER TABLE command to change generation expression   This adds a new ALTER TABLE subcommand ALTER COLUMN ... SET EXPRESSION that changes the generation expression of a generated column.   The syntax is not standard but was adapted from other SQL implementations.

You may have noticed a file called postmaster.pid inside your data directory. This file gets created when Postgres first starts up, and gets removed on a clean shutdown. It seems to contain some random numbers and strings, but what do they all mean?

The file will look like this:

2757 /home/greg/pg/17/data 176540940 5432 /tmp * 8675309 12 ready

Here is a quick cheat sheet of the contents: