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To NULL, or not to NULL, that is the question!

As we already stated in earlier articles in this blog [1 and 2] it is a good idea to use NULL values properly in MariaDB and MySQL.

UNDO logs in InnoDB system tablespace ibdata1

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We see sometimes at customers that they have very big InnoDB system tablespace files (ibdata1) although they have set innodb_file_per_table = 1.

So we want to know what else is stored in the InnoDB system tablespace file ibdata1 to see what we can do against this unexpected growth.

First let us check the size of the ibdata1 file:

MariaDB indexing of NULL values

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In the recent MariaDB DBA advanced training class the question came up if MariaDB can make use of an index when searching for NULL values... And to be honest I was not sure any more. So instead of reading boring documentation I did some little tests:

Search for NULL

First I started with a little test data set. Some of you might already know it:

MariaDB/MySQL Schulungstermine 2019

Jetzt sind auch noch die letzten MariaDB und MySQL Schulungstermine für 2019 festgelegt und veröffentlicht.

Mit unseren drei Schulungspartnern in Essen, Köln und Berlin bietet FromDual zur Zeit insgesamt 12 öffentliche Schulungen zum Thema MariaDB und MySQL an.

Es sind dies:

MariaDB/MySQL Environment MyEnv 2.0.1 has been released

FromDual has the pleasure to announce the release of the new version 2.0.1 of its popular MariaDB, Galera Cluster and MySQL multi-instance environment MyEnv.

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

Schulung MariaDB/MySQL für Fortgeschrittene vom 12.-16. 11. in Köln

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In unserer FromDual Schulung MariaDB/MySQL für Fortgeschrittene vom 12. bis 16. November in Köln hat es zur Zeit noch 3 Plätze frei.

Anmelden können Sie sich direkt bei unserem Schulungspartner GfU in Köln.

Cool new features in FromDual Backup and Recovery Manager 2.0.0

A while ago we released our FromDual Backup and Recovery Manager (brman) 2.0.0 for MariaDB and MySQL. So what are the new cool features of this new release?

First of all brman 2.0.0 is compatible with MariaDB 10.3 and MySQL 8.0:

Select Hello World FromDual with MariaDB PL/SQL

MariaDB 10.3 was released GA a few weeks ago. One of the features which interests me most is the MariaDB Oracle PL/SQL compatibility mode.

So its time to try it out now...

Special MySQL and MariaDB trainings 2018 in English

Due to a strong customer demand FromDual offers 2018 two extra MySQL/MariaDB trainings with its Training partner The Linuxhotel in Essen (Germany). Those trainings are in English.

  • MariaDB Performance Tuning on 5 and 6 September 2018 (2 days).
  • Advanced MySQL/MariaDB training on 26 to 30 November 2018 (5 days).

More information about the contents of the trainings can be found at Advanced MySQL and MariaDB training.

MySQL sys Schema in MariaDB 10.2

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MySQL has introduced the PERFORMANCE_SCHEMA (P_S) in MySQL 5.5 and made it really usable in MySQL 5.6 and added some enhancements in MySQL 5.7 and 8.0.

MariaDB 10.2 New Features - Slides available

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The Chemnitz Linux Days 2018 in Chemnitz (Germany) 10/11 March 2018 are over for more than a week now and IMHO it was a huge success.

I was following many very interesting talks, met a lot of interesting people and learned a lot!

MySQL Environment MyEnv 2.0.0 has been released

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.

Advanced MySQL Enterprise Training by FromDual

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Due to the increasing demand FromDual has developed an Advanced MySQL Enterprise Training for DBAs and DevOps. After testing this training extensively with some selected customers last year we offer this MySQL Enterprise Training in 2018 for a broader audience.

The MySQL Enterprise Training addresses MySQL DBAs and DevOps which are already familiar with MySQL and approach now the challenge to operate a serious MySQL Enterprise infrastructure.

MySQL 8.0.4-rc is out

Yesterday MySQL 8.0.4-rc came out. The Release Notes are quite long.
But caution: Do a BACKUP before upgrading...

I experienced some nice surprises. First I have to admit that I did not read the Release Notes or anything else. Reading manuals is for Girlies! Possibly something is written in there which is of importance. But I expect that it just works as usual...

Short term notice: Percona XtraDB Cluster training in English 7/8 February 2018 in Germany

FromDual offers short term a Percona XtraDB Cluster and MySQL Galera Cluster training (2 days) in English.

The training will take place in the Linuxhotel in Essen/Germany on February 7/8 2018.

There are already enough registrations so it is certain the training will take place. But there are still free places for some additional participants.

Advanced MySQL and MariaDB training in Cologne 2018

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End of February, from February 26 to March 2 (5 days), FromDual offers an additional training for DBAs and DevOps: our most visited Advanced MySQL and MariaDB training.

This training is hold in the training facilities of the FromDual training partner GFU Cyrus GmbH in Cologne-Deutz (Germany).

There are already enough registrations so it is certain the training will take place. But there are still free places for at least 3 additional participants.

The training is in German.

Oracle releases MySQL security vulnerability fixes 2018-01

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As in every quarter of the year Oracle has released yesterday its recommendation for the MySQL security updates. This is called, in Oracle terminology, Critical Patch Update (CPU) Advisory.

This CPU is published for all Oracle products. But FromDual is only interested in MySQL related topics. So let us concentrate on those.

Galera Cluster and Antivirus Scanner on Linux

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Today we had to investigate in a very strange behaviour of IST and SST on a MariaDB Galera Cluster.

The symptom was, that some Galera Cluster nodes took a very long time to start. Up to 7 minutes. So the customer was concluding that the Galera Cluster node does an SST instead of an IST and was asking why the SST happens.

It have to be mentioned here, that the MariaDB error log is very confusing about whether it is an SST or an IST. So the customer was confused and concluded, that MariaDB Galera Cluster was doing an SST instead of IST.

First Docker steps with MySQL and MariaDB

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The Docker version of the distributions are often quite old. On Ubuntu 16.04 for example:

shell> docker --version 
Docker version 1.13.1, build 092cba3

But the current docker version is 17.09.0-ce (2017-09-26). It seems like they have switched from the old version schema x.y.z to the new year.month.version version schema in February/March 2017.

MariaDB master/master GTID based replication with keepalived VIP

Some of our customers still want to have old-style MariaDB master/master replication clusters. Time goes by, new technologies appear but some old stuff still remains.

Galera Load Balancer the underestimated wallflower

There are some pretty sophisticated Load Balancers for Galera Clusters setups out in the market (ProxySQL, MaxScale, HAproxy, ...). They have many different exotic features. You can nearly do everything with them. But this comes at the cost of complexity. Non of them is simple any more.

Find evil developer habits with log_queries_not_using_indexes

Recently I switched on the MariaDB slow query logging flag log_queries_not_using_indexes just for curiosity on one of our customers systems:

Storing BLOBs in the database

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We have sometimes discussions with our customers whether to store LOBs (Large Objects) in the database or not. To not rephrase the arguments again and again I have summarized them in the following lines.

The following items are more or less valid for all large data types (BLOB, TEXT and theoretically also for JSON and GIS columns) stored in a MySQL or MariaDB (or any other relational) database.

MySQL Enterprise Backup Incremental Cumulative and Differential Backup

Preparing the MySQL Enterprise Administrator Training I found that the MySQL Enterprise Backup Incremental Backup is not described very well. Thus I tried it out and wrote down this how-to:

Incremental Differential Backup



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