Showing entries 9316 to 9325 of 44058
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Jörg Brühe: The Upcoming Leap Second

The press, be it the general daily newspaper or the computer magazines, is currently informing the public about an upcoming leap second, which will be taken in the night from June 30 to July 1 at 00:00:00 UTC. While we Europeans will enjoy our well-deserved sleep then, this will be at 5 PM (17:00) local time on June 30 for Califormia people, and during the morning of July 1 for people in China, Japan, Korea, or Australia. (Other countries not mentioned for the sake of brevity.) This is different from last time, when the leap second was taken in the night from Saturday to Sunday (2012-July-1 00:00:00 UTC), so it was a weekend everywhere on the globe.

We have got several requests from our customers about this upcoming leap second, whether they need to take any special precautions or whether they "are safe". Well, obviously nobody is "safe" from the leap second in the sense that it would circumvent them, everybody will encounter it on their …

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Practical MySQL Performance Optimization (July 2 webinar)

Applications often become impacted by MySQL performance. Optimization is the obvious solution but where to start? Join me on July 2 at 11 a.m. Pacific and I’ll show you how to optimize MySQL in a practical way – spending time on what gives you the best return. Many of you have heard me talk on this topic before and this updated presentation will get you up to speed on the latest areas to consider when improving MySQL performance.

I’ll be pointing out the most important things you need to get right for each of the following:

  • Hardware
  • MySQL Configuration
  • Schema and Queries
  • Application Architecture

I’ll also share some tools and techniques to focus on the queries most important for your application. At the end of this webinar, aptly titled “ …

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TokuDB and Binlog Group Commit in MySQL 5.7

The MySQL 5.7.6 release notes describe a change to the binary log group commit algorithm that can improve the performance of write intensive applications when the binary log is enabled (noted with Bug #19424075).  This change is probably inspired by the experiment reported in MySQL bug #73202.

There is a long history of tweaking the binary log group commit algorithm and the InnoDB storage engine to scale performance.  Mark Callaghan describes the work done on this problem at Facebook. …

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Plan to deprecate PROCEDURE ANALYSE

In the MySQL team, we have been refactoring the SQL parser to be more maintainable. Gleb Shchepa lists the goals of this project in more details on the MySQL Server Team blog.

As part of this, we have identified the feature PROCEDURE ANALYSE as something that we would like to deprecate. For added context, here is a demonstration:

mysql> SELECT * FROM City procedure analyse()\G
*************************** 1. row ***************************
             Field_name: world.city.ID
              Min_value: 1
              Max_value: 4079
             Min_length: 1
             Max_length: 4
       Empties_or_zeros: 0
                  Nulls: 0
Avg_value_or_avg_length: 2040.0000 …
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MySQL Cluster: Una introducción en Español.

MySQL Cluster: El ‘qué’ y el ‘cómo’.

Para aquellos que encuentran mucho sobre MySQL en Inglés pero poco en Español: mi pequeña aportación.
En el enlace tenéis información sobre qué es MySQL Cluster y cómo funciona. Incluso con ejemplos técnicos para romper las barreras y ayudar a simplificarlo (espero).

¡A disfrutar!

VALIDATE PASSWORD PLUGIN with mysql_secure_installation in 5.7.7-rc

While testing installation steps with MySQL 5.7.7-rc, surely you will find much more improvements, changes, deprecated functionality and etc.

The interesting one is activating VALIDATE PASSWORD PLUGIN via mysql_secure_installation script. Which we use by mean “securing” MySQL installations.

I will write a separate topic about MySQL 5.7.7-rc installation steps from source, with related BUG reports.

So after first run:

[root@centos7_vm mysql]# bin/mysql_secure_installation --socket=/opt/mysql/datadir/mysqld-new.sock
Securing the MySQL server deployment.
Connecting to MySQL server using password in '/root/.mysql_secret'

If you notice, now script trying to connect to MySQL using a temporary password which is generated for root@localhost and logged into hidden .mysql_secret file.

VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of …
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Debugging Transaction Conflicts in Galera Cluster

If you are using Galera Cluster in multi-master mode, you will most likely run into transaction conflicts if two clients attempt to modify the same row at the same time. Such conflicts are reported a deadlock errors to the application.

Legacy applications are frequently unable to handle transaction conflicts properly and may not provide sufficient information to debug the source of the problem.

If the wsrep_log_conflicts option is set, Galera can output all the information about transaction conflicts that is available to it to the error log. As it is a dynamic option, you can enable it while the server is running, collect some entries for examination, and disable it to avoid filling up the log.

Decoding the Output

The output from wsrep_log_conflicts may look a bit intimidating at first, but in fact contains a lot of information that can be used to pin-point the offending application, module or SQL operation. The …

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Success Story: VividCortex Improves Reliability at DC Energy

DC Energy is a trader in the commodities markets that relies heavily on MySQL. Since trading is time-sensitive, database management and minimal system downtime is a high priority. Prior to deploying VividCortex, DC Energy used query logs and custom tools, scripts and metrics to find and resolve problems. Internal tools did not provide a way to quickly review and assess the enormous amount of data available, and gaining insight into performance was time consuming.

In March 2013, DC Energy began using VividCortex. Joe Kelly, DC Energy associated, highlighted the benefits since installation:

VividCortex has an intuitive interface, and it’s clearly built by a team that understands monitoring because it only shows us what we need to know. It does not overwhelm us with a lot of information we don’t want. Everything I want is accessible, and I am not bogged down by extraneous information.

This has led to faster diagnosis and …

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Fibonacci Sequence Procedure

Well it has been awhile since I posted, sorry about that. Today I was watching reruns of the TV show Fringe and when Walter referenced the Fibonacci Sequence I got side tracked with MySQL options for this.

Now this post already existed:


So I took that post and expanded on it a little, the result is a procedure that you can call and return the range within the Fibonacci Sequence that you are after.

The procedure is below:

delimiter //
CREATE PROCEDURE `Fibonacci`(IN POS INT, IN RANG INT, IN LIMTED INT)
BEGIN
       select FORMAT(Fibonacci,0) AS Fibonacci from (

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MariaDB Galera Cluster 5.5.44 and 10.0.20 now available

The MariaDB project is pleased to announce the immediate availability of MariaDB Galera Cluster 10.0.20 and MariaDB Galera Cluster 5.5.44. These are Stable (GA) releases.

Download MariaDB Galera Cluster 10.0.20

Release Notes Changelog What is MariaDB Galera Cluster?

Download …

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