Database Administration *

One of the open challenges in the database world is keeping a database consistent across multiple DBMS instances (nodes) that independently handle client connections. The crux of the issue is ensuring that if one node fails, the others keep running smoothly — accepting connections, committing transactions, and maintaining consistency without a hitch. Think of it like a single DBMS instance staying operational despite a faulty RAM stick or intermittent access to multiple CPU cores.

My name is Andrey Lepikhov, and I’d like to kick off a discussion about the multi-master concept in PostgreSQL: its practical value, feasibility, and the tech stack needed to make it happen. By framing the problem more narrowly, we might find a solution that’s genuinely useful for the industry.

Traditional approaches to SQL query generation often rely on instruction-tuned language models, but these can be inefficient and inaccurate. In this article, we’ll explore a new method based on reinforcement learning for model fine-tuning, which can improve both the accuracy and efficiency of SQL generation.

Hello, Habr! We continue the series of articles on the innovations of the Tantor Postgres 17.5.0 DBMS, and today we will talk about authorization support via OAuth 2.0 Device Authorization Flow is a modern and secure access method that allows applications to request access to PostgreSQL on behalf of the user through an external identification and access control provider, such as Keycloak, which is especially convenient for cloud environments and microservice architectures (the feature will also be available in PostgreSQL 18). In this article, we'll take a step-by-step look at configuring OAuth authorization in PostgreSQL using Keycloak: configure Keycloak, prepare PostgreSQL, write an OAuth token validator in PostgreSQL, and verify successful authorization via psql using Device Flow.

The myth of the magical fast=true parameter is still alive and well, but in distributed databases, another contender appears: distributed=true. Neither one will save you if you don’t rethink your schema, sharding keys, sequences, queries, and migration process. We walk through every corner with a clear-eyed approach — from choosing sharding keys and colocated tables to CDC, topologies, and foreign key constraints — showing where performance really improves, where it gets more expensive, and how to deal with it.

Migration from Oracle to vanilla PostgreSQL hits roadblocks with packages, autonomous transactions, and collections—they simply don’t exist there. We’ll break down why ora2pg stumbles, how native implementations of these mechanisms in Postgres Pro Enterprise make life easier, and how ora2pgpro translates PL/SQL semantically correctly, without hacks or crude regex.

September 25th marks the release of PostgreSQL 18. This article covers the March CommitFest and concludes the series covering the new features of the upcoming update. This article turned out quite large, as the last March CommitFest is traditionally the biggest and richest in new features.

You can find previous reviews of PostgreSQL 18 CommitFests here: 2024-07, 2024-09, 2024-11, 2025-01.

TDE comes in many flavors — from encryption at the TAM level to full-cluster encryption and tablespace markers. We take a close look at Percona, Cybertec/EDB, Pangolin/Fujitsu, and show where you lose performance and reliability, and where you gain flexibility.

On top of that, Vasily Bernstein, Deputy head of product development, and Vladimir Abramov, senior security engineer, will share how Postgres Pro Enterprise implements key rotation without rewriting entire tables — and why AES-GCM was the clear choice.

It all started as a joke by the office coffee machine. But, as with every decent joke, it suddenly sounded worth trying — and before we knew it, we were knee-deep in an experiment that turned out to be anything but trivial, complete with a whole minefield of gotchas.

It began simply: while everyone else was busy debating hardware tuning and squeezing out extra TPS from their systems, we thought — why not just shove a huge chunk of data into PostgreSQL and see how it holds up? Like, really huge. Say, a one-petabyte database. Let’s see how it survives that.

It was December 10, the boss wanted the report by January 20, and New Year was less than a month away. And that itch that all engineers know? It hit hard.

During load testing of Tantor Postgres databases or other PostgreSQL-based databases using the standard tool pgbench, specialists often encounter non-representative results and the need for repeated tests due to the fact that details of the environment (such as DBMS configuration, server characteristics, PostgreSQL versions) are not recorded. In this article we are going to review author's pg_perfbench, which is designed to address this issue. It ensures that scenarios are repeatable, prevents the loss of important data, and streamlines result comparison by registering all parameters in a single template. It also automatically launches pgbench with TPC-B load generation, collects all metadata on the testing environment, and generates a structured report.

pg_stat_statements is the standard PostgreSQL extension used to track query statistics: number of executions, total and average execution time, number of returned rows, and other metrics. This information allows to analyze query behavior over time, identify problem areas, and make informed optimization decisions. However, in systems with high contention, pg_stat_statements itself can become a bottleneck and cause performance drops. In this article, we will analyze in which scenarios the extension becomes a source of problems, how sampling is structured, and in which cases its application can reduce overhead.

In this article, I will tell you about a-few-years journey of scaling the Elasticsearch cluster in production environment, which is one of the vital elements of the iPrice technology stack. 
I will describe challenges we encountered and how we approached them.

    Once upon a time our DBA team had a task. We had to move a ZooKeeper ensemble which we had been using for Clickhouse cluster. Everyone is used to moving an ensemble by moving its data files. It seems easy and obvious but our Clickhouse cluster had more than 400 TB replicated data. All replication information had been collected in ZooKeeper cluster from the very beginning. At the end of the day we couldn’t miss even a row of data. Then we looked for information on the internet. Unfortunately there was a good tutorial about 3.4.5 and didn’t fit our version 3.6.2. So we decided to use “the extending” for moving our ensemble.

• We’ll find out what is an in-memory database, or IMDB. When and how are they better than disk solutions?
• Then, we’ll consider their architecture. What about their efficiency, reliability, and scaling?
• Then, we’ll delve into technical details. Data types, iterators, indexes, transactions, programming languages, replication, and connectors.

In this article, we benchmark the performance of MySQL 8 default configuration vs. innodb_dedicated_server enabled configuration vs. the configuration recommended by MySQL Performance Tuning Service.

1. How to design the architecture of a trigger platform for real-time marketing?
2. How to arrange a data structure that would be in line with the requirements of a marketing strategy for interacting with clients?
3. How to ensure the stable operations of the  system under very heavy workloads? 

This post is handling the following situation - how to setup up simple Mysql services with group replication being dockerized. In our case, we’ll take the latest Mysql (version 8.x.x)

FYI: all mentioned code (worked and tested manually) located here.

I will skip not interested steps like ‘what is Mysql, Docker and why we choose them, etc’. We want to set up possibly trouble proof DB. That’s our plan.

• our requirements for the database, universal solutions, and the CAP theorem
• whether the database + application server in one approach is a silver bullet
• the evolution of the platform and the databases used in it
• the number of Tarantools we use and how we came to this

Academic data warehouse design recommends keeping everything in a normalized form, with links between. Then the roll forward of changes in relational math will provide a reliable repository with transaction support. Atomicity, Consistency, Isolation, Durability — that's all. In other words, the storage is explicitly built to safely update the data. But it is not optimal for searching, especially with a broad gesture on the tables and fields. We need indices, a lot of indices! Volumes expand, recording slows down. SQL LIKE can not be indexed, and JOIN GROUP BY sends us to meditate in the query planner.