SQL on Netdata

Using FOR UPDATE SKIP LOCKED For Queue Workflows

Fri, 29 Aug 2025 00:00:00 +0000

One of the most common and powerful patterns in modern application development is the job queue. Whether you’re sending emails, processing images, or running complex calculations, offloading tasks to background workers is essential for building responsive and scalable systems. Many developers reach for dedicated queueing software like RabbitMQ or Redis, but for many use cases, your primary PostgreSQL database already has all the tools you need to build a robust, transactional, and incredibly performant job_queue_postgres.

Whats The Difference Between PostgreSQL vs MySQL

Mon, 09 Jun 2025 00:00:00 +0000

When building an application, one of the most fundamental decisions you’ll make is choosing the right database. For many developers, this choice boils down to two of the most popular open-source relational databases in the world: PostgreSQL and MySQL. Both are powerful, reliable, and backed by strong communities, but they operate on different philosophies and excel in different areas.

Making the right choice between PostgreSQL vs MySQL isn’t about finding a single “best” database, but understanding which one aligns with your application’s specific needs. This guide breaks down the critical differences in their architecture, features, performance characteristics, and ideal use cases to help you make an informed decision for your next project.

All Types Of Databases: Advantages & Examples

Thu, 17 Apr 2025 00:00:00 +0000

This is a tech-savvy exploration of database types! From the structured precision of relational models to the dynamic versatility of NoSQL, we’re diving deep into each DB type, unpacking their perks, and dishing out some examples to help you pick the perfect fit for your digital toolbox.

What Is A Database?

A database is a structured collection of stored data, that allows easy access, management, and updating. They come in various types to suit different needs; from hierarchical databases that organize data in a tree-like format to relational databases that use tables and relationships among those data. Databases are essential to build any tech product from small mobile apps to large-scale enterprise systems. They help you handle, search, and efficiently utilize large data sets.

What Is Cardinality In Databases: A Comprehensive Guide

Mon, 29 Jan 2024 00:00:00 +0000

An Introduction To Cardinality

Cardinality is a fundamental concept in databases that plays a crucial role in designing efficient databases and optimizing query performance. For those new to databases, understanding what is cardinality is essential for effective data management. This comprehensive guide will explain the meaning of cardinality, its types, and its impact on database performance, making it accessible for both beginners and intermediate users.

What Is Cardinality In Databases?

Cardinality in databases refers to the uniqueness of data values contained in a column. It essentially measures how many distinct values exist in a column compared to the total number of rows in a table.

Monitor any SQL metrics with Netdata (and Pandas ❤️)

Wed, 22 Feb 2023 00:00:00 +0000

We recently got this great feedback from a dear user in our Discord:

I would really like to use Netdata to monitor custom internal metrics that come from SQL, not a fan of having 10 diff systems doing essentially the same thing as is, Netdata is pretty much all there in that regard, just needs a few extra features.

This is great and exactly what we want, a clear problem or improvement we could make to help make that users monitoring life a little easier.

CockroachDB Monitoring

Mon, 01 Jan 0001 00:00:00 +0000

CockroachDB Monitoring

CockroachDB is a cloud-native distributed SQL database designed to scale horizontally and survive datacenter failures. Monitoring CockroachDB is crucial for maintaining the health, performance, and reliability of your database infrastructure. Netdata provides a comprehensive CockroachDB monitoring tool that enables real-time visibility and enhanced troubleshooting capabilities to ensure optimal database operations.

What Is CockroachDB?

CockroachDB is a distributed SQL database, similar in functionality to Google Spanner, designed to deliver strong fault tolerance, consistency, and scalability across distributed environments. Its architecture allows for seamless scaling and resilience, making it an ideal choice for modern, high-demand database operations.

CockroachDB result is ambiguous: ambiguous commit errors and how to handle them

Mon, 01 Jan 0001 00:00:00 +0000

Your application received result is ambiguous (PostgreSQL error code 40003, statement_completion_unknown) from CockroachDB. The transaction may have committed. It may have been aborted. The database does not know, and neither do you.

This is not a bug. It is a correctness property of CockroachDB’s distributed commit protocol. When the transaction coordinator loses contact with the leaseholder during the final commit step, or during the last statement of an implicit transaction, it cannot determine whether the commit succeeded. Rather than guess and risk a silent double-apply, CockroachDB surfaces the ambiguity.

MySQL online DDL still blocking: ALGORITHM, LOCK, and the copy phase

Mon, 01 Jan 0001 00:00:00 +0000

Online DDL in MySQL is not lock-free. Even with ALGORITHM=INPLACE or ALGORITHM=INSTANT, and even with LOCK=NONE, every online DDL operation passes through a brief window where it upgrades its metadata lock (MDL) to exclusive. That window is short, but it is real, and it is the single most common reason an “online” schema change still stalls a busy production table.

This article explains the three-phase MDL model that online DDL uses, why ALGORITHM=INPLACE with LOCK=NONE can still block, what the copy phase actually does, and how third-party tools such as pt-online-schema-change and gh-ost change the picture. It assumes you already understand the broader MySQL mental model. See the hub page for the failure-pattern catalogue that frames metadata lock stalls as one of MySQL’s characteristic outage archetypes.

SQL Database agnostic Monitoring

Mon, 01 Jan 0001 00:00:00 +0000

SQL Database agnostic Monitoring

What Is SQL Database Monitoring?

SQL databases are an integral part of most modern applications, serving as the backbone for data storage and management. Monitoring SQL databases involves tracking performance metrics, uptime, and other critical parameters to ensure database queries run smoothly and efficiently. It helps in preemptively identifying issues such as slow queries, connection bottlenecks, or resource exhaustion.

Monitoring SQL Databases With Netdata

To effectively monitor SQL databases, Netdata utilizes an openmetrics (Prometheus) exporter. Netdata can ingest data from any Prometheus exporter, allowing users to set up automated dashboards, alerts, and more. This is achieved without needing a dedicated Prometheus server or Grafana, making it an efficient and streamlined solution for your database monitoring needs. With Netdata’s integration, you can maintain real-time insights into your database health and performance seamlessly.