Database

Common Problems 114133

RPM database corruption prevents package transactions

🔴 Critical   ⏱ 5–30 min  Last verified: 16 March 2026 Affected versions: RHEL 10.0 RHEL 10.1 📖 ~1 min read Table of contents Problem Summary Symptoms Diagnostics Root Cause Primary Fix Verification Prevention Rollback Automation Command Reference Escalation Related Notes Problem Summary rpm/dnf transactions fail because rpmdb is inconsistent or locked. Symptoms Messages include […]

Read more
How to Monitor MariaDB Performance with mytop on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Monitor MariaDB Performance with mytop on RHEL 10

Introduction RHEL 10 ships with a stable, security-hardened base that makes deploying monitor mariadb performance with mytop both straightforward and auditable. This tutorial covers the complete procedure for how to Monitor MariaDB Performance with mytop on RHEL 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for network-facing services. […]

Read more
How to Configure Prometheus AlertManager on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Prometheus AlertManager on RHEL 9

Prometheus AlertManager is a standalone component of the Prometheus monitoring stack responsible for deduplicating, grouping, routing, and dispatching alerts to notification channels such as Slack, email, and PagerDuty. While Prometheus evaluates alerting rules and fires alerts, it is AlertManager that decides who gets notified, when, and how — preventing alert storms and on-call fatigue through […]

Read more
How to Create Databases and Users in MariaDB on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Create Databases and Users in MariaDB on RHEL 10

Introduction RHEL 10 ships with a stable, security-hardened base that makes deploying create databases and users in mariadb both straightforward and auditable. This tutorial covers the complete procedure for how to Create Databases and Users in MariaDB on RHEL 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for […]

Read more
Complete Guide: How to Use Nested Queries in SQL 2026

Complete Guide: How to Use Nested Queries in SQL 2026

Learning how to use nested queries in SQL is one of the most powerful and frequently applied skills for developers, backend engineers, database administrators, data analysts, full-stack builders, DevOps professionals, startup founders, business intelligence specialists, and anyone writing advanced, efficient, single-statement queries in 2026.

Read more
Complete Guide: How to Use GROUP BY and ORDER BY in SQL

Complete Guide: How to Use GROUP BY and ORDER BY in SQL 2026

Learning how to use GROUP BY and ORDER BY in SQL is one of the most essential and frequently executed skills for developers, backend engineers, database administrators, data analysts, full-stack builders, DevOps professionals, startup founders, business intelligence specialists, and anyone turning raw data into summarized, sorted, report-ready insights in 2026.

Read more
Complete Guide: How to Work with Dates and Times in SQL

Complete Guide: How to Work with Dates and Times in SQL 2026

Learning how to work with dates and times in SQL is one of the most essential and frequently used skills for developers, backend engineers, database administrators, data analysts, full-stack builders, DevOps professionals, startup founders, business intelligence specialists, and anyone building time-sensitive applications in 2025–2026. Mastering how to work with dates and times in SQL lets you calculate durations, find time differences, add/subtract intervals, format timestamps, filter by date ranges, compute ages, track race times, schedule events, analyze user activity, and power dashboards, reports, analytics, and every feature that involves temporal data.

Read more
Complete Guide: How to Use Mathematical Expressions and Aggregate Functions in SQL 2026

Complete Guide: How to Use Mathematical Expressions and Aggregate Functions in SQL 2026

Learning how to use mathematical expressions and aggregate functions in SQL is one of the most powerful and frequently used skills for developers, backend engineers, database administrators, data analysts, full-stack builders, DevOps professionals, startup founders, business intelligence specialists, and anyone turning raw database data into business insights in 2025–2026. Mastering how to use mathematical expressions and aggregate functions in SQL lets you perform calculations directly inside queries — compute revenue, profit margins, growth rates, averages, extremes, counts, inventory levels, pricing adjustments, and KPI summaries — without exporting data to spreadsheets or external tools.

Read more
Complete Guide: How to Use Comparison and IS NULL Operators in SQL

Complete Guide: How to Use Comparison and IS NULL Operators in SQL 2026

Learning how to use comparison and IS NULL operators in SQL is one of the most foundational and frequently executed skills for developers, backend engineers, database administrators, data analysts, full-stack builders, DevOps professionals, startup founders, business intelligence specialists, and anyone writing precise, efficient queries in 2025–2026. Mastering how to use comparison and IS NULL operators in SQL lets you filter rows with exact matches, ranges, inequalities, null checks, and logical exclusions — powering search, reporting, analytics, user filters, dashboards, APIs, data validation, and every data-driven feature in your application.

Read more
Ultimate Guide: How to Create and Manage Tables in SQL 2026

Tables in SQL – Ultimate Guide

Learning how to create and manage tables in SQL is one of the most foundational and frequently used skills for developers, database designers, backend engineers, data analysts, full-stack builders, DevOps professionals, and anyone working with relational databases in 2025–2026. Tables are the core structure of every relational database — they store your data in rows and columns, define relationships, enforce rules, and power everything from simple CRUD apps to massive enterprise systems, e-commerce platforms, SaaS products, analytics dashboards, and financial backends.

Read more
CHAT