Search Results for: LEFT JOIN

Optimize Your SQL With Percona’s Online Query Advisor!

Wouldn’t it be nice if you could get expert advice on your SQL queries to find problems in them, the same way that programmers can use lint-check tools to warn about bugs in their C?

Such a simple mistake, but it’s the kind of thing that James Bond movies are made of, isn’t it? […]

Moving Subtrees in Closure Table Hierarchies

Many software developers find they need to store hierarchical data, such as threaded comments, personnel org charts, or nested bill-of-materials. Sometimes it’s tricky to do this in SQL and still run efficient queries against the data. I’ll be presenting a webinar for Percona on February 28 at 9am PST. I’ll describe several solutions for storing […]

Dropping unused indexes

Vadim wrote some time ago about how to find unused indexes with single query. I was working on the system today and found hundreds of unused indexes on dozens of tables so just dropping indexes manually did not look fun. So I extended Vadim’s query to generate ALTER TABLE statements automatically. I also made it […]

Unused indexes by single query

Usually unused indexes are devil, they waste diskspace, cache, they make INSERT / DELETE / UPDATE operations slower and what makes them worse – it is hard to find them. But now ( with userstatsV2.patch) you can find all unused indexes (since last restart of mysqld) by single query

As you see query […]

MySQL and OpenStack deep dive: Dec. 10 webinar

Fact: MySQL is the most commonly used database in OpenStack deployments. Of course that includes a number of MySQL variants – standard MySQL by Oracle, MariaDB, Percona Server, MySQL Galera, Percona XtraDB Cluster, etc. However, there are many misconceptions and myths around the pros and cons of these MySQL flavors. Join me and my friend […]

Auto-bootstrapping an all-down cluster with Percona XtraDB Cluster

One new feature in Percona XtraDB Cluster (PXC) in recent releases was the inclusion of the ability for an existing cluster to auto-bootstrap after an all-node-down event.  Suppose you lose power on all nodes simultaneously or something else similar happens to your cluster. Traditionally, this meant manually re-bootstrapping the cluster, but not any more. How it […]

Percona Live London 2014 Wrap Up

The 2014 edition of Percona Live London brought together attendees from 30 countries to hear insightful talks from leaders in the MySQL community. The conference kicked off on Monday with a full day of tutorials followed by the very popular Community Dinner featuring a double decker bus shuttle from the conference to the event. Tuesday […]

Facebook MySQL database engineers ready for Percona Live London 2014

With 1.28 billion active users, Facebook MySQL database engineers are active and extremely valuable contributors to the global MySQL community. So naturally they are also active participants of Percona Live MySQL conferences! And next week’s Percona Live London 2014 (Nov. 3-4) is no exception. (Register now and use the promotional code “Facebook” to save £30!) […]

Rackspace doubling-down on open-source databases, Percona Server

Founded in 1998, Rackspace has evolved over the years to address the way customers are using data – and more specifically, databases. The San Antonio-based company is fueling the adoption of cloud computing among organizations large and small. Today Rackspace is doubling down on open source database technologies. Why? Because that’s where the industry is […]

When (and how) to move an InnoDB table outside the shared tablespace

In my last post, “A closer look at the MySQL ibdata1 disk space issue and big tables,” I looked at the growing ibdata1 problem under the perspective of having big tables residing inside the so-called shared tablespace. In the particular case that motivated that post, we had a customer running out of disk space in his […]