Search Results for: mysql reduce io

Reducer.sh – A powerful MySQL test-case simplification/reducer tool

Let me start by saying a big “thank you” to the staff at Oracle for deciding to open source reducer.sh. It’s a tool I developed whilst I was working for them several years ago. Its sole purpose is to do one thing – but do it good: test-case simplification. So, let’s say some customer just […]

The value of MySQL Support

Years ago when I worked for the MySQL Support organization at the original MySQL AB, we spoke about MySQL Support as insurance and focused on a value proposition similar to that of car insurance. For your car to be fully covered, you must purchase car insurance before the incident happens – in fact most places […]

Free MySQL QA & Bash/Linux Training Series

Welcome to the MySQL QA Training Series! If you have not read our introductory blog post on pquery yet, I’d recommend reading that one first to get a bit of background. The community is enthuastic about pquery, and today I am happy to announce a full training series on pquery and more. Whether you are […]

5 free handy tools for monitoring and managing MySQL replication

MySQL Replication is very simple to set up. In this post I’ll discuss its importance and five handy tools for monitoring and managing MySQL replication. What is MySQL Replication? It’s the process of copying the (real-time events) data from one master instance to another slave instance and maintaining the redundant consistent data in a different […]

The future of MySQL quality assurance: Introducing pquery

Being a QA Engineer, how would you feel if you had access to a framework which can generate 80+ crashes – a mix of hitting developer introduced assertions (situations that should not happen), and serious unforeseen binary crashes – for the world’s most popular open source database software – each and ever hour? What if you could […]

Faster fingerprints and Go packages for MySQL

I’m happy to announce Go packages for MySQL. Particularly exciting is a new query fingerprint function which is very fast and efficient, but I’ll talk about that later. First, go-mysql is currently three simple Go packages for parsing and aggregating MySQL slow logs. If you’ve been following Percona development, you’ve no doubt heard of Percona Cloud Tools (PCT), a […]

Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug. First […]

The MySQL Query Cache: How it works, plus workload impacts (good and bad)

Query caching is one of the prominent features in MySQL and a vital part of query optimization. It is important to know how it works as it has the potential to cause significant performance improvements – or a slowdown – of your workload. The MySQL query cache is a global one shared among the sessions. It caches […]

How a set of queries can be killed in MySQL using Percona Toolkit’s pt-kill

You might have encountered situations where you had to kill some specific select queries that were running for long periods and choking the database. This post will go into more detail with an example of report query offloading. Report query (select) offloading to a slave server is a common practice to reduce the workload of the […]

Avoiding MySQL ALTER table downtime

MySQL table alterations can interrupt production traffic causing bad customer experience or in worst cases, loss of revenue. Not all DBAs, developers, syadmins know MySQL well enough to avoid this pitfall. DBAs usually encounter these kinds of production interruptions when working with upgrade scripts that touch both application and database or if an inexperienced admin/dev […]