NDB is mainly an In-memory database. We have however also the possibility to
store non-indexed columns on disk. This data uses a page cache as any
other normal disk-based DBMS.

Interestingly with the increases of memory sizes one could think that
disk data becomes less important for MySQL Cluster. The answer is actually
the opposite.

The reason is again the HW development. NDB is designed with predictable
latency as a very basic requirement. In the past disks meant hard drives. Access
time to a hard disk was several milliseconds at best. Given that our requirement
was to handle complex transactions within 10 milliseconds disk data storage
was out of the question.

Modern HW is completely different, they use SSD devices, first attached through
the SATA interface that enabled up to around 500 MByte per second and
a few thousand IO …

I just read an article called Low-Overhead Asynchronous Checkpointing in
Main-Memory Database Systems. It was mentioned in a course in Database
Systems at Carnegie-Mellon University, see here.

In MySQL Cluster 7.6.4 we released a new variant of our checkpointing designed
for modern HW with TBytes of main memory. I think studying this implementation
will be very worthwhile both for users of NDB, but also for researchers in DBMS
implementations. It implements a new class of checkpoint algorithms that is currently
a research topic in the database research community.

It was interesting to compare our approach that I called Partial LCP with approaches
taken by other commercial in-memory databases and with the approach presented
in the paper.

LCP is Local …

Percona announces the release of Percona Toolkit 3.0.8 on March 16, 2018.

Percona Toolkit is a collection of advanced open source command-line tools, developed and used by the Percona technical staff, that are engineered to perform a variety of MySQL®, MongoDB® and system tasks that are too difficult or complex to perform manually. With over 1,000,000 downloads, Percona Toolkit supports Percona Server for MySQL, MySQL, MariaDB®, Percona Server for MongoDB and MongoDB.

Percona Toolkit, like all Percona software, is free and open source. You can download packages from the website or install from official repositories.

This …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

SCALE16x is over. Percona had a large showing — both Peter Zaitsev & myself had talks, and the booth in the expo hall saw Rick Golba, Marc Sherwood, and Dave Avery also pop by. The lead scanner suggests we had several hundred conversations — read Dave Avery’s summary. My talk went well, though during Q&A the number of questions I got about MariaDB Server was quite interesting (considering it wasn’t part of my talk!). It is clear people are concerned about compatibility (because I spent close to 45 minutes after my talk answering Q&A outside too).

I got to catch up with …

FromDual has the pleasure to announce the release of the new version 2.0.0 of its popular MySQL, Galera Cluster and MariaDB multi-instance environment MyEnv.

The new MyEnv can be downloaded here.

In the inconceivable case that you find a bug in the MyEnv please report it to the FromDual bug tracker.

Any feedback, statements and testimonials are welcome as well! Please send them to feedback@fromdual.com.

Upgrade from 1.1.x to 2.0.0

# cd ${HOME}/product
# tar xf /download/myenv-2.0.0.tar.gz
# rm -f myenv
# ln -s myenv-2.0.0 myenv

Plug-ins

If you are using plug-ins for …

FromDual has the pleasure to announce the release of the new version 2.0.0 of its popular MySQL, Galera Cluster and MariaDB multi-instance environment MyEnv.

The new MyEnv can be downloaded here. How to install MyEnv is described in the MyEnv Installation Guide.

In the inconceivable case that you find a bug in the MyEnv please report it to the FromDual bug tracker.

Any feedback, statements and testimonials are welcome as well! Please send them to feedback@fromdual.com.

Upgrade from 1.1.x to 2.0.0

MyEnv 2.0.0 requires an new PHP …

MySQL has over the years grown into a considerable family of products and components. Years ago, someone running MySQL would typically have a single Server instance. Advanced users might have two and run replication. These days, MySQL is much more of a distributed system, offering advanced replication technology for HA, load balancing, systems for monitoring […]

In this blog post, we’ll look at how you can verify query performance using ProxySQL.

In the previous blog post, I showed you how many information can you get from the “stats.stats_mysql_query_digest” table in ProxySQL. I also mentioned you could even collect and graph these metrics. I will show you this is not just theory, it is possible.

These graphs could be very useful to understand the impact of the changes what you made on the query count or execution time.

I used our all-time favorite benchmark tool called Sysbench. I was running the following query:

UPDATE sbtest1 SET c=? WHERE k=?

There was no index on “k” when I started the test. During the test, I …

This Saturday I will be teaching Database Basics with MySQL and there are literally just two seats  left!  The MySQL Community Team is always looking for ways to reach new audiences and we would like to make this class available to other groups (So let me know if you are interested).

And six hours is a really short time so it only scratches the surface.  Maybe we also need some intermediate classes above and beyond the introduction.

Business has continuously desired to derive insights from information to make reliable, smarter, real-time, fact-based decisions. As firms rely more on data and databases, information and data processing is the core of many business operations and business decisions. The faith in the database is total. None of the day-to-day company services can run without the underlying database platforms. As a consequence, the necessity on scalability and performance of database system software is more critical than ever. The principal benefits of the clustered database system are scalability and high availability. In this blog, we will try to compare Oracle RAC and Galera Cluster in the light of these two aspects. Real Application Clusters (RAC) is Oracle’s premium solution to clustering Oracle databases and provides High Availability and …