October 21, 2014

InnoDB scalability issues due to tables without primary keys

Each day there is probably work done to improve performance of the InnoDB storage engine and remove bottlenecks and scalability issues. Hence there was another one I wanted to highlight: Scalability issues due to tables without primary keys This scalability issue is caused by the usage of tables without primary keys. This issue typically shows […]

Want to archive tables? Use Percona Toolkit’s pt-archiver

Percona Toolkit’s pt-archiver is one of the best utilities to archive the records from large tables to another tables or files. One interesting thing is that pt-archiver is a read-write tool. It deletes data from the source by default, so after archiving you don’t need to delete it separately. As it is done by default, you […]

Understanding the maximum number of columns in a MySQL table

This post was initially going to be two sets of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on, ponder those questions and come up with your own answers… and see if you’re right or can prove me wrong! […]

Analyzing Slow Query Table in MySQL 5.6

Next week I’m teaching an online Percona Training class, called Analyzing SQL Queries with Percona Toolkit.  This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database response time is being spent. This month we saw the GA release of MySQL 5.6, and I wanted to check if any […]

Is MySQL 5.6 slower than MySQL 5.5?

There have been a number reports/benchmarks showing MySQL 5.6 to be slower than MySQL 5.5 on variety of workloads. There are many possible reasons and I believe we will learn about many of them in the next few weeks and months as MySQL 5.6 is starting to get production battle-tested and there is inflow of […]

Is there room for more MySQL IO Optimization?

I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL […]

Migrating several single standalone MySQL server to one Percona XtraDB Cluster… MariaDB to the rescue !

Some weeks ago I had to migrate some independent MySQL servers (some standard MySQL masters, and some just standalone) to a Percona XtraDB Cluster of 3 nodes. So the easiest way would be to configure each node to become also an asynchronous slave of one of the production servers. Like illustrated here: But in this […]

Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd […]

Using pt-table-checksum with Percona XtraDB Cluster

As of Percona Toolkit v2.1.5, pt-table-checksum works correctly with Percona XtraDB Cluster, but it doesn’t work quite like a traditional replication setup because cluster nodes are not like traditional replicas.  In this post I demonstrate how to use pt-table-checksum with Percona XtraDB Cluster. First, you’ll need Percona Toolkit v2.1.5 or newer and Percona XtraDB Cluster 5.5.27-23.6 […]

Thank you for joining us at Percona Live, NYC 2012

Over 200 attendees attended last week’s Percona Live NY event. This year we structured event different than in 2011 with Tutorial Day allowing for in-depth 3 hour presentations for those looking to dive deep into specific topics. We also added an Expo Hall which allowed a lot of MySQL Ecosystem participant to meet their prospective […]