Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
Showing entries 1 to 10 of 36147 10 Older Entries
Shinguz: Why you should take care of MySQL data types
+0 Vote Up -0Vote Down

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:

  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `data` varchar(64) DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `data` (`data`)

*************************** 1. row ***************************
           id: 1 …
  [Read more...]
The differences between IDEMPOTENT and AUTO-REPAIR mode
+0 Vote Up -0Vote Down

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 recovery after a crash where perhaps the data on the slave may get out of sync with the master. Under normal circumstances this should not happen but in the real world sometimes it does. …

  [Read more...]
Looking inside the MySQL 5.7 document store
+1 Vote Up -0Vote Down

In this blog, we’ll look at the MySQL 5.7 document store feature, and how it is implemented.

Document Store

MySQL 5.7.12 is a major new release, as it contains quite a number of new features:

  1. Document store and “MongoDB” like NoSQL interface to JSON storage
  2. Protocol X / X Plugin, which can be used for asynchronous queries (I will write about it as well) …
  [Read more...]
MySQL Keywords and Reserved Words
+0 Vote Up -0Vote Down

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 this!((╯°□°)╯︵ ┻━┻` int); …

  [Read more...]
pt-online-schema-change (if misused) can’t save the day
+0 Vote Up -0Vote Down

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

…  [Read more...]
Webinar Thursday May 26: Troubleshooting MySQL hardware resource usage
+0 Vote Up -0Vote Down

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...]
Join us for our European Polyglot Persistence Meetups Tour this summer!
+0 Vote Up -0Vote Down

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.

Sign up for a Polyglot Persistence Meetup

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...]
Percona XtraBackup 2.4.3 is now available
+0 Vote Up -0Vote Down

is glad to announce the GA release of Percona XtraBackup 2.4.3 on May 23rd, 2016. Downloads are available from our download site and from apt and yum repositories.

  [Read more...]
Windows Nano Server Technical Preview 5 and MySQL
Employee_Team +0 Vote Up -0Vote Down

Windows Nano Server is a deployment option of the upcoming Windows Server 2016. It is a “headless” version of Windows Server, pared back to provide the bare essentials necessary to host server / “born in the cloud” applications such as MySQL.…

MySQL slave promotion with- and without using GTID
+0 Vote Up -0Vote Down

MySQL Replication can be fragile: whenever it encounters a connectivity error, it will retry and if it is a serious error, it will simply stop. Obviously in the latter case, you will need to repair the broken replication yourself.

The most common problems with replication are when it stops due to either master failure or network problems. In case the master fails, the whole topology becomes read-only and this means the write queries cannot be applied anymore. This is where normally you would promote one of the replicas to become the new master. To illustrate the difference in promotion between GTID and non-GTID cases, we will go through the …

  [Read more...]
Showing entries 1 to 10 of 36147 10 Older Entries

Planet MySQL © 1995, 2016, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.