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MySQL 5.5.40 Overview and Highlights

MySQL 5.5.40 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

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

There were 0 “Functionality Added or Changed” bugs this time, and 18 bugs overall fixed.

Out of the 18 bugs, most seemed rather minor or obscure, but there are 3 I think are worth noting (all 3 are InnoDB-related, regressions, and serious if you encounter them, so best to be aware of them):

  • InnoDB: An ALTER TABLE … ADD FOREIGN KEY operation could cause a serious error. (Bug #19471516, Bug #73650)
  • InnoDB: With a transaction isolation level less than or equal to READ COMMITTED, gap locks …
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MySQL 5.7.5: GROUP BY respects functional dependencies!

Today, Oracle announced the availability of the Development Milestone Release 15 of MySQL 5.7.5. The tagline for this release promises "Enhanced Database Performance and Manageability". That may sound rather generic, the actual list of changes and improvements is simply *huge*, and includes many items that I personally find rather exciting! Perhaps I'm mistaken but I think this may be one of the largest number of changes packed into a MySQL point release that I've witnessed in a long time. The list of changes includes improvements such as:

  • InnoDB improvements: Simplified tablespace recovery, support for spatial indexes, dynamic configuration
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Using MySQL Workbench

I’ve been setting up a simplified lab environment to let my students learn use in class. This added content will show them how to do reverse engineering with MySQL Workbench.

It’s a complete Fedora image with MySQL and Oracle Database 11g for the course. The uncompressed image is 14GB and the compressed image is 5.3GB. I chose Fedora because it’s the smallest open source image that supports both environments, and Fedora is the closest to Red Hat and Oracle Unbreakable Linux. I’m inclined to make the instance available generally but haven’t figured out the best way to do that.

Here are the new instructions I’m adding and if you have any input leave it as a comment.

You connect as the student user, which puts you in the /home/student directory. Once connected to the Fedora OS, you open a Terminal session by clicking on Activities in the upper right hand corner, and then you …

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JSON UDF functions version 0.3.2 have been released

Today new version of JSON UDF functions: 0.3.2 was released. This is development release which contains new functionality. You can download functions from the MySQL Labs website.

What is new?

New function `JSON_COUNT` added. This function returns number of children of the key path specified. If no key path specified, number of children of the root element is returned. Bug #70580/17584692 ADD FUNCTION `JSON_COUNT` TO COUNT SIZE OF JSON DOCUMENT

mysql> select json_count('{"MySQL Central": ["conference", 2014]}') as 'root count',
    ­> json_count('{"MySQL Central": ["conference", 2014]}', 'MySQL Central') as 'first element count'\G     
                                                   
************************ 1. row ************************
         root count: 1
first element count: 2
1 row in set …
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MySQL Workbench 6.2: It’s all about the Query

Improved Visual Explain

In MySQL 5.7, the Optimizer Team has been doing great work in refactoring as well as innovation with the new Cost Model. The improved Visual Explain enables the DBA to now get deeper insights into Optimizer decision making, for improved performance tuning of queries.   The UI was also improved to allow easier navigation in large query plans.

Streamlined Query Results Panel

The query results panel was updated to centralize the many features related to result sets into a single location. Result Grid, Form Editor, Field Types, Query Stats, Execution Plan (including the traditional and Visual Explain) and the new Spatial Viewer are all easily accessible from a single interface.

Run SQL …

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Importing related MySQL tables into an Excel Data Model using MySQL for Excel

In this blog post we are going to talk about one of the features included since MySQL for Excel 1.3.0. 

Importing MySQL data into Excel is a common and important operation in MySQL for Excel. There may be times when you need to analyze the data stored in several MySQL tables or views, (possibly in an ExcelPivotTable which will be the subject of a future blog post), and to do it you need to dump the data into Excel as the first step. Starting with MySQL for Excel 1.3.0 we introduced a feature that allows you to import the data from multiple MySQL tables or views in a single operation.

Remember you can install the latest GA or maintenance version using the MySQL Installer or optionally you can download directly any GA or non-GA version from the  …

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TokuDB Read Free Replication : Details and Use Cases

The biggest innovation in TokuDB v7.5 is Read Free Replication (RFR). I blogged a few days ago posting a benchmark showing how much additional throughput can be achieved on a replication slave, while at the same time lowering the read IO operations to almost zero. The official documentation on the feature is available here.

In this second blog I want to cover the requirements for RFR, as well as some interesting use-cases for the technology.

RFR Requirements The only requirement on the master is that …[Read more]
More then 1000 columns – get transactional with TokuDB

Recently I encountered a specific situation in which a customer was forced to stay with the MyISAM engine due to a legacy application using tables with over 1000 columns. Unfortunately InnoDB has a limit at this point. I did not expect to hear this argument for MyISAM. It is usually about full text search or spatial indexes functionality that were missing in InnoDB, and which were introduced in MySQL 5.6 and 5.7, respectively, to let people forget about MyISAM. In this case though, InnoDB still could not be used, so I gave the TokuDB a try.

I’ve created a simple bash script to generate a SQL file with …

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mysqldump or Percona XtraBackup? Backup Strategies for MySQL Galera Cluster

September 25, 2014 By Severalnines

Coming up with a backup strategy that does not affect database performance or lock your tables can be tricky. How do you backup your production database cluster without affecting your applications? Should you use mysqldump or Percona Xtrabackup? When should you use incremental backups? Where do you store the backups? In this blog post, we will cover some of the common backup methods for Galera Cluster for MySQL/MariaDB, and how you can get the most out of these. 

 

Backup Method

 

There are various ways to backup your Galera Cluster data:

  • xtrabackup (full physical backup)
  • xtrabackup (incremental physical backup)
  • mysqldump (logical backup)
  • binary logging 
  • replication slave

 

Xtrabackup (full backup)

Xtrabackup is an open-source MySQL hot …

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The MySQL 5.7.5 Milestone Release is Available

The MySQL Development team is happy to announce our 5.7.5 development milestone release (DMR), now available for download at dev.mysql.com.  You can find the full list of changes and bug fixes in the 5.7.5 release notes.  Here are the highlights. Enjoy!

Scalability

Improve scalability by not using thr_lock locks for InnoDB tables (WL#6671) : This work by Dmitry Lenev improves InnoDB scalability by not using thr_lock locks for InnoDB tables. For InnoDB tables we now rely on MDL + InnoDB row locks. This patch shows good performance/scalability improvements in the single table Sysbench OLTP_RO/ POINT_SELECT tests for InnoDB on multi-core …

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