Before you start creating database entities, spend some time designing your database to ensure that it is fit for your purpose. The time you invest in this process saves a lot of time and trouble later. Professional database designers fine-tune their design using a process called 'normalization'. The normalization process takes your database design through a number of 'normal forms', which aim to ensure efficient data access, greater query flexibility, and easier maintenance.

For example, the First Normal Form (or '1NF') ensures that all your database columns contain only a single value. A column that contains multiple data values is difficult to access and keep up to date. It also ensures that each table row only represents a single 'real world' item. Like all the other normal forms, this encourages you to split your data across multiple tables, with less rows in each table. You can quickly see the benefits of this approach as your database …

MariaDB Roadshow Helsinki

One could say that MariaDB originates from Finland’s capital Helsinki. In fact so does MySQL. It was in the Helsinki area that MySQL saw daylight. It was here that Monty Widenius laid the ground for MySQL already in the 80’s, maybe even 1979, when he created UNIREG from which parts were reused when he together with the other 2 founders of MySQL released the first version of MySQL in 1995.

Last week, 19 years later, a MariaDB event was held in Helsinki. It was SkySQL that arranged the first in a row of this year’s MariaDB Roadshow events. The agenda included a walkthrough of MariaDB 10.0, some roadmap and MariaDB high availability options, which consisted of MariaDB Galera Cluster and …

While working with an error that my students surfaced in the Oracle Database 12c, I blogged about the limit of using a subquery in an Oracle INSERT statement, and I discovered something when retesting it in MySQL. It was a different limitation. I was also surprised when I didn’t find any mention of it through a Google search, but then I may just not have the right keywords.

The original test case uses a subquery to create a multiple row result set for an INSERT statement. Unfortunately, I discovered that you can’t always embed a UNION or UNION ALL inside a subquery. At least, you can’t when you call the subquery inside an INSERT statement. For example, let’s create a DESTINATION table and then we’ll try to insert records with a query that …

The development version of PECL/mysqlnd_ms now has an very early version of distributed (2PC/XA) transaction support tailored for use with clusters of MySQL servers. XA transactions can span multiple servers in a cluster to ensure transaction guarantees among them. In real life, there is always, at some point, a sequence of work on your data for which atomicity, consistency, isolation, and durability must be given. The early generation of NoSQL sharding solutions has a weak spot here. How do you, as a developer, ensure a logical operation affecting two shards is either applied to both or none? Either you don’t …

In my last post, I gave a technical explanation of the performance characteristics of partitioned collections in TokuMX 1.5 (which is right around the corner) and partitioned tables in relational databases. Given those performance characteristics, in this post, I will present some best practices when using this feature in TokuMX or TokuDB. Note that these best practices are designed for TokuMX and TokuDB only, which use …

In this post I would like to review how my dumper for MySQL works from the point of view of locks. Since 0.6 serie we have different options, so I will try to explain how they work

As you may know mydumper is multithreaded and this adds a lot of complexity compared with other logical backup tools as it also needs to coordinate all threads with the same snapshot to be consistent. So let review how mydumper does this with the default settings.

By default mydumper uses 4 threads to dump data and 1 main thread

Main Thread

• FLUSH TABLES WITH READ LOCK

Dump Thread X

• START TRANSACTION WITH CONSISTENT SNAPSHOT;
• dump non-InnoDB tables

Main Thread

• UNLOCK TABLES

Dump Thread X

• dump InnoDB tables

As you can see in this case we need FTWRL for two things, coordinate transaction’s snapshots …

MySQL 5.5.38 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://downloads.skysql.com/archive/index/p/mysql/v/5.5.38

This release, similar to the last 5.5 release, is mostly uneventful.

Out of the mere 13 bugs, most were benign, but I thought there were two worth mentioning (just because one is a slight performance improvement for InnoDB, and the other relates to slave consistency, so always important to see if it could affect you):

1. InnoDB: For each insert, memset would be called three times to allocate memory for system fields. To reduce CPU usage, the three memset calls are now combined into a single call. (Bug #17858679, Bug #71014)
2. Replication: When …

Tungsten Replicator is an innovative and reliable open source tool that can solve your most complex MySQL replication problems. In this webinar we will introduce Replicator installation and show you how to use key Replicator features effectively with MySQL.  

Replication is a powerful technology that takes knowledge and planning to use effectively. This webinar gives you the background that

FairWarning® solutions have audited well over 120 billion events, each of which was processed and stored in a MySQL database. FairWarning is the world's leading supplier of privacy monitoring solutions for electronic health records, relied on by over 1,200 Hospitals and 5,000 Clinics to keep their patients' data safe. In January 2014, FairWarning was awarded the highest commendation in healthcare IT as the first ever Category Leader for Patient Privacy Monitoring in the "2013 Best in KLAS: Software & Services" report[1].

FairWarning has used MySQL as their solutions’ database from their start in 2005 to worldwide expansion and market leadership. FairWarning recently migrated their solutions from MyISAM to InnoDB and updated from MySQL 5.5 to 5.6. Following are some of benefits they’ve had as a …

Good MySQL talent is hard to find. Each day I get several ‘I am looking for a MySQL DBA’ or ‘MySQL Developer needed’. Long story short, post your opening on http://forums.mysql.com as it catches the most eyes of MySQL Professionals.