April 21, 2014

Using MMM to ALTER huge tables

Few months ago, I wrote about a faster way to do certain table modifications online. It works well when all you want is to remove auto_increment or change ENUM values. When it comes to changes that really require table to be rebuilt – adding/dropping columns or indexes, changing data type, converting data to different character […]

Data Recovery Toolkit for InnoDB Version 0.1 Released

As Peter mentioned in one of previous posts, we’ve done huge work developing robust strategies of InnoDB data recovery to provide our customers effective data recovery services and one of major parts of these strategies is our toolkit for InnoDB data recovery. Today I’m proud to announce its first public release which was used to […]

Using CHAR keys for joins, how much is the overhead ?

I prefer to use Integers for joins whenever possible and today I worked with client which used character keys, in my opinion without a big need. I told them this is suboptimal but was challenged with rightful question about the difference. I did not know so I decided to benchmark. The results below are for […]

MySQL Installation and upgrade scripts.

I generally find MySQL Sever sufficiently tested, meaning at least minor version upgrades rarely cause the problems. Of course it is not perfect and I remember number of big issues when some releases could not be used due to behavior changes in them and when something had to be rolled back in the next release. […]

Are PHP persistent connections evil ?

As you probably know PHP “mysql” extension supported persistent connections but they were disabled in new “mysqli” extension, which is probably one of the reasons some people delay migration to this extension. The reason behind using persistent connections is of course reducing number of connects which are rather expensive, even though they are much faster […]

Long PRIMARY KEY for Innodb tables

I’ve written and spoke a lot about using short PRIMARY KEYs with Innodb tables due to the fact all other key will refer to the rows by primary key. I also recommended to use sequential primary keys so you do not end up having random primary key BTREE updates which can be very expensive. Today […]

Watch out for Marketing benchmarks

Whenever I see benchmark results I try to understand if it is technical benchmark – made by people seeking the truth or it is done by Marketing department to wash your brains. Watch out. Whenever you treat marketing benchmarks as technical ones, you make make wrong decision. Take a look at MySQL 5.0 Benchmarks Whitepaper […]

Heartbleed: Separating FAQ From FUD

If you’ve been following this blog (my colleague, David Busby, posted about it yesterday) or any tech news outlet in the past few days, you’ve probably seen some mention of the “Heartbleed” vulnerability in certain versions of the OpenSSL library. So what is ‘Heartbleed’, really? In short, Heartbleed is an information-leak issue. An attacker can […]

DBA 101: Sometimes forgotten functionality in the MySQL client

The MySQL client has some functionalities some of us never use. Why would you use them and what is the added value of this? Every DBA and developer has had a moment when he or she needs to connect to a MySQL database using the command line tool. Therefore I’ve written down an explanation of […]

Useful MySQL 5.6 features you get for free in PXC 5.6

I get a lot of questions about Percona XtraDB Cluster 5.6 (PXC 5.6), specifically about whether such and such MySQL 5.6 Community Edition feature is in PXC 5.6.  The short answer is: yes, all features in community MySQL 5.6 are in Percona Server 5.6 and, in turn, are in PXC 5.6.  Whether or not the new […]