Back when the first version of the MariaDB Java Client was released, someone asked in the comments about the performance characteristics of the driver compared to ConnectorJ. I answered with hand-waving, saying that nobody does anything stupid, the performance of the drivers would be roughly the same, but I promised to measure it and tell the world one day. And now that day has come. The day where three MySQL JDBC drivers (ConnectorJ, MariaDB JDBC, and Drizzle JDBC) are compared against each other. Unlike the server, which gets benchmarking attention all the time, there is no standard benchmark for connectors, so I needed to improvise, while trying to keep the overhead of the server minimal. So I did something very primitive to start. I used my two favorite queries:

• DO 1 — this one does not retrieve a result set, and thus can be seen as a small “update”.
• SELECT 1 — the minimal …

Sysbench OLTP, transactions per second

When dealing with high performance, low latency storage devices, such as SSD cards, one finds bottlenecks in new places. This is a story about such a bottle neck and how to work around it.

One unique feature of InnoDB is the double write buffer. This buffer was implemented to recover from half-written pages. This can happen in case of a power failure while InnoDB is writing a page (16KB = 32 sectors) to disk. On reading that page, InnoDB would be able to discover the corruption from the mismatch of the page checksum. However in order to recover, an intact copy of the page would be needed.

The double write buffer provides such a copy. Whenever InnoDB flushes a page to disk, it is first written to the double write buffer. Only when the buffer is safely flushed to disk, InnoDB writes the page to the final destination. When recovering, InnoDB scans the double write buffer and for each …

We discuss INFORMATION_SCHEMA with plenty of examples on useful queries. In this week's Ear Candy, we talk about resident versus virtual memory on Linux, and in At the Movies has a video about MongoDB.

Events
DB Hangops in May will be Wed May 8th and 22nd noon pacific time.
Upcoming MySQL tech tours

Training
SkySQL Trainings
Tungsten University trainings

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MySQL, the most popular open source database brings you great performance. You can see the performance details in http://dimitrik.free.fr/blog/. To help you get the most from MySQL's performance, take the MySQL for Performance Tuning course.

This four day instructor-led training course covers:

• Performance Tuning Basic
• Performance Tuning Tools
• MySQL Server Tuning
• MySQL Query Cache
• Storage Engines
• Schema Design and Performance
• Performance Tuning Extras

This course is available in three delivery types:

• Training-on-Demand: Take this course at your own …

A little while ago I blogged about (and open sourced) an Impala-powered soccer visualization demo, designed to demonstrate just how responsive Impala queries can be. Since not everyone has the time or resources to run the project themselves, we’ve decided to host it ourselves on an EC2 instance. You can try the visualization; we’ve also opened up the Impala web interface, where you can see query profiles and performance numbers, and Hue (username and password are both ‘test’), where you can run your own queries on the dataset.

Deploying Impala on EC2

While there are …

One of the main responsibilities of any database administrator is to keep a close eye on how database performance is impacting size and storage. Decisions will have to be made on whether or not to make changes within the database structure or application itself, or to make the changes on the storage and resource side [...] Read More

A default installation of MySQL is easy to perform, but if you really want your databases to sing, you should tune them like you would tune a piano. In MySQL tuning pertains to either the application or the database system. In this post, we cover some common tuning techniques and best practices to increase your [...] Read More

A few weeks ago I wrote about “MySQL Performance at High Concurrency” and why it is important, which was followed up by Vadim’s post on ThreadPool in Percona Server providing some great illustration on the topic. This time I want to target an opposite question: why MySQL performance at low concurrency is important for you.

I decided to write about this topic as a number of recent blog posts and articles look at MySQL performance starting with certain concurrency as the low point. For example, …

Percona’s Kenny Gryp leads a recent MySQL workshop

Percona will be in Chicago and London the week of April 8th delivering two 2-day MySQL workshops. For our MPB readers, we are offering a 15% discount. Just use MPB15A when purchasing your tickets to one or both MySQL workshops.

• Scaling and Optimization for MySQL on Monday & Tuesday, April 8 & 9
  • This MySQL workshop will cover:
    • Apply architecture scaling strategies that make the most sense, including …

This week we discuss changed behavior of variables in MySQL 5.6. In ear candy we talk about a cloud-based service to play with SQL on different databases, and At the Movies is Stewart Smith of Percona talking about MySQL in the Cloud as a Service during Linux Conf Australia in Canberra.

Changed behavior of variables in 5.6
boolean variables can be set to ON/OFF 1/0 TRUE/FALSE

Variables with changes:
log_slave_updates

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