In talking to existing MongoDB users and TokuMX evaluators, I’ve often heard that the performance of MongoDB is very good as long as your working data set fits in RAM. The story continues that if your working data set grows to be larger than the RAM on your server, the built-in sharding capabilities of MongoDB allow you to scale horizontally.

As my benchmarking presentation at Percona Live 2013 pointed out, I’m never one to accept something without at least running it once myself. I decided to run my Sysbench for MongoDB benchmark on an in-memory workload, meaning that all of the data fits …

MySQL Tech Day @Paris

We're happy to announce you that MySQL Tech Day will take place in Paris on Oct 10, 2013 in Oracle main office. It'll be a full day event giving you an occasion to listen directly from Oracle developers about most of the improvements made recently within MySQL 5.6 and 5.7 development.

The MySQL engineering team constantly works to bring you huge performance improvements with each new release of MySQL. Here are four ways to help you get the most from these improvements

Tap into Sveta Smirnova's MySQL performance expertise on October 1st 2013 at 10am Central European Time, by attending the 1-day virtual seminar, Troubleshooting MySQL Performance with Sveta Smirnova. Sveta starts with basics, working towards more advanced cases that DBAs usually need years of experience to identify or solve. Click here to learn more about this seminar and to register for the event.

The …

and the video can be directly played in your browser at http://technocation.org/node/697/play or downloaded (170Mb) at http://technocation.org/node/697/download.

and the video can be directly played in your browser at http://technocation.org/node/697/play or downloaded (170Mb) at http://technocation.org/node/697/download.

I do not recall seeing an announcement about it, pancreatitis but I went looking for the videos today and lo and behold, they were up! Forgive me if I missed a post about it….but if you also missed it, here they are:

<A …

In my recent SQL work for a large Swiss bank, I have maintained nested database view monsters whose unnested SQL code amounted up to 5k lines of code, joining the same table over and over again in separate subselects combined via UNION operations. This monster performed in way under 50ms, no matter how we queried … Continue reading The Myth About Slow SQL JOIN Operations →

Memory Leak

Memory Flame Graph    

Your application memory usage is steadily growing, and you are racing against time to fix it. This could either be memory growth due to a misconfig, or a memory leak due to a software bug. For some applications, performance can begin to degrade as garbage collection works harder, consuming CPU. If an application grows too large, performance can drop off a cliff due to paging (swapping), or the application may be killed by the system (OOM killer). You want to take a quick look before either occurs, in case it’s an easy fix. But how?

Debugging growth issues involves checking the application config and memory usage, either from application or system tools. Memory leaks are much …

In 4 days, the MySQL Performance Tuning training teaches you practical, safe and highly efficient ways to optimize performance for the MySQL Server. It will help you:

• Evaluate the architecture
• Understand and use the tools.
• Configure the database for performance.
• Tune application and SQL code.
• Tune the server.
• Examine the storage engines.
• Assess the application architecture.
• Understand general tuning concepts.

You can take this instructor-led course as a:

• Training-on-Demand offering: Start training within 24 hours of regsitration, taking this course at your own pace through streaming video of instructor delivery and …

This week we talk with Tim Callaghan of Tokutek about TokuMX, a take on MongoDB. Ear Candy is perror on Windows and At the Movies is a presentation from the SkySQL and MariaDB Solutions Day 2013 about Tokutek.

TokuMX

Replication between MySQL and MongoDB using Tungsten a couple of years ago at Open DB Camp in Sardinia (2011).

Previous interviews with Tokutek folks in:
Episode 39

read more

Before creating a unique index in TokuMX or TokuDB, ask yourself, “does my application really depend on the database enforcing uniqueness of this key?” If the answer is ANYTHING other than yes, do not declare the index to be unique. Why? Because unique indexes may kill your write performance. In this post, I’ll explain why.

Unique indexes are a strange beast: they have no impact on standard databases that use B-Trees, such as MongoDB and MySQL, but may be horribly painful for databases that use write optimized data structures, like TokuMX’s Fractal Tree(R) indexes. How? …

When analyzing response time, or latency, you need much more information than an average provides. The average, commonly the arithmetic mean, shows the index of central tendency. But, as I found in earlier posts, the tendency is often not central, but may be skewed by outliers, or split by multiple modes. How often these factors occur was determined quantitatively, using tests and a survey of hundreds of production servers and different types of latency: over 95% had six-sigma outliers, and at least 20% had multiple modes. While these numerical results are useful, nothing beats a visualization, such as a histogram, …