Thanks to everyone who joined us yesterday for our ClusterControl 1.3 release webinar!
Johan Andersson, CTO at Severalnines and creator of ClusterControl, walked us through the latest features of the 1.3 release and demonstrated them live as well. In addition to an overview of ClusterControl’s deployment, monitoring, management and scaling functionalities for MySQL, MariaDB, Percona Server, MongoDB and PostgreSQL, Johan focussed our attention on new features around key management, operational reports and more.
One feature-set that triggered particular interest in yesterday’s audience was …[Read more...]
A customer reported last month that MySQL does a full table scan
(FTS) if a query was filtered by a
INT value on a
VARCHAR column. First I told him that this is not
true any more because MySQL has fixed this behaviour long time
ago. He showed me that I was wrong:
CREATE TABLE `test` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `data` varchar(64) DEFAULT NULL, `ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`), KEY `data` (`data`) ) ENGINE=InnoDB; EXPLAIN SELECT * FROM test WHERE data = 42\G *************************** 1. row *************************** id: 1 …[Read more...]
I posted recently Lossless RBR for MySQL 8.0 about a concern I have about moving to minimal RBR in MySQL 8.0. This seems to be the direction that Oracle is considering, but I am not sure it is a good idea as a default setting. I talked about a hypothetical new replication mode lossless RBR and also about … Continue reading The differences between IDEMPOTENT and AUTO-REPAIR mode
In this blog, we’ll look at the MySQL 5.7 document store feature, and how it is implemented.
MySQL 5.7.12 is a major new release, as it contains quite a number of new features:
Peter already wrote the …[Read more...]
I've seen some confusion on what constitutes a keyword or a reserved word in MySQL. The manual defines them, and has a complete list. Reserved words are a special subset of keywords, and you can't use a reserved word as an identifier unless you quote it with backticks. I discourage the use of backticks to quote identifiers, because it allows you to use lots of words and characters in your identifier that you'll probably regret later. For example:
`` mysql> create tableYou will regret
((╯°□°）╯︵ ┻━┻` int); …
In this blog post we’ll discuss pt-online-schema-change, and how to correctly use it.
Always use pt-osc?
Altering large tables can be still a problematic DBA task, even now after we’ve improved Online DDL features in MySQL 5.6 and 5.7. Some ALTER types are still not online, or sometimes just too expensive to execute on busy production master.
So in some cases, we may want to apply an
first on slaves, taking them out of traffic pool one by one and bringing them back …[Read more...]
Join Sveta on Thursday, May 26, 2016, at 10 am PDT (UTC-7) for her webinar Troubleshooting MySQL hardware resource usage.
MySQL does not just run on its own. It stores data on disk, and stores data and temporarily results in memory. It uses CPU resources to perform operations, and a network to communicate with its clients.
In this webinar, we’ll discuss common resource …[Read more...]
We’ve been gearing up for this in the past months and we’re delighted to announce the first dates of our European Polyglot Persistence Meetups this summer. We’re starting off with Amsterdam, then moving on to Dublin, Paris, Berlin, Stockholm and London.
Some of you may ask what Polyglot Persistence is all about …
Polyglot Persistence means that when storing data, it is best to use multiple data storage technologies, chosen based upon the way data is being used by the application. In a world where …[Read more...]