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Benchmarking Percona Server TokuDB vs InnoDB

May 7, 2013 By Vadim Tkachenko 29 Comments

After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong suit) with some roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements [...]

Filed Under: Benchmarks, MySQL, Percona Server Tagged With: Benchmarking, InnoDB, Percona Server, TokuDB

More on MySQL transaction descriptors optimization

April 26, 2013 By Alexey Kopytov Leave a Comment

Since my first post on MySQL transaction descriptors optimization introduced in Percona Server 5.5.30-30.2 and a followup by Dimitri Kravchuk, we have received a large number of questions on why the benchmark results in both posts look rather different. We were curious as well, so we tried to answer that question by retrying benchmarks on [...]

Filed Under: Benchmarks, MySQL Tagged With: MySQL transaction descriptors, Optimization

How to recover table structure from InnoDB dictionary

April 22, 2013 By Aleksandr Kuzminsky 4 Comments

To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from [...]

Filed Under: Insight for DBAs, MySQL Tagged With: InnoDB, kuzminsky, Recovery, SYS_COLUMNS, SYS_FIELDS, SYS_INDEXES, SYS_TABLES

Repair MySQL 5.6 GTID replication by injecting empty transactions

March 26, 2013 By Miguel Angel Nieto 1 Comment

In a previous post I explained how to repair MySQL 5.6 GTID replication using two different methods. I didn’t mention the famous SET GLOBAL SQL_SLAVE_SKIP_COUNTER = n for a simple reason, it doesn’t work anymore if you are using MySQL GTID. Then the question is: Is there any easy way to skip a single transaction? [...]

Filed Under: MySQL

InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By Ernie Souhrada 1 Comment

I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: Ernie Souhrada, FTS, FullText Search, InnoDB, MyISAM, MySQL 5.6

Feature preview: Compact backups in Percona XtraBackup

January 29, 2013 By Vadim Tkachenko 11 Comments

We continue to improve Percona XtraBackup, and today I would like to give a preview for one feature which comes in next Percona XtraBackup 2.1 release. This feature is “Compact backups”, and let me explain what it does. As you may know InnoDB PK (Primary Key) contains all data, and all secondary indexes are only [...]

Filed Under: MySQL, Percona Software Tagged With: Percona XtraBackup, Vadim Tkachenko

Logging Deadlock errors

September 19, 2012 By Miguel Angel Nieto 4 Comments

The principal source of information for InnoDB diagnostics is the output of SHOW ENGINE INNODB STATUS but there are some sections that are not very useful. For example, LATEST DETECTED DEADLOCK only shows, as the name implies, the latest error detected. If you have 100 deadlocks per minute you will be able to see only [...]

Filed Under: Insight for Developers, MySQL

When is MIN(DATE) != MIN(DATE) ?

September 4, 2012 By Ernie Souhrada 5 Comments

Inspiration for this post is courtesy of a friend and former colleague of mine, Greg Youngblood, who pinged me last week with an interesting MySQL puzzle. He was running Percona Server 5.5.21 with a table structure that looks something like this:

CREATE TABLE foo (
 id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 uid INT UNSIGNED NOT NULL,
 update_time DATETIME NOT NULL,
 ....
 INDEX `uid` (uid, update_time),
 INDEX `bar` (some_other_columns)
 ....
) ENGINE=InnoDB;

CREATE TABLE foo (

id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,

uid INT UNSIGNED NOT NULL,

update_time DATETIME NOT NULL,

....

INDEX `uid` (uid, update_time),

INDEX `bar` (some_other_columns)

....

) ENGINE=InnoDB;

When he ran this query:

SELECT MIN(update_time) FROM foo WHERE update_time IS NOT NULL AND update_time <> '0000-00-00 00:00:00';

1	SELECT MIN(update_time) FROM foo WHERE update_time IS NOT NULL AND update_time <> '0000-00-00 00:00:00';

The result came back as 2012-06-22 10:28:16. [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL

Full Text Search Webinar Questions Followup

August 24, 2012 By Bill Karwin 5 Comments

I presented a webinar this week to give an overview of several Full Text Search solutions and compare their performance. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. During my webinar, a number of attendees asked some good questions. Here are their questions and my [...]

Filed Under: Events and Announcements, Insight for Developers, MySQL

Recovery after DROP & CREATE

August 22, 2012 By Aleksandr Kuzminsky 1 Comment

In a very popular data loss scenario a table is dropped and empty one is created with the same name. This is because mysqldump in many cases generates the “DROP TABLE” instruction before the “CREATE TABLE”:

DROP TABLE IF EXISTS `actor`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `actor` (
  `actor_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
  `first_name` varchar(45) NOT NULL,
  `last_name` varchar(45) NOT NULL,
  `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`actor_id`),
  KEY `idx_actor_last_name` (`last_name`)
) ENGINE=InnoDB AUTO_INCREMENT=201 DEFAULT CHARSET=utf8;
/*!40101 SET character_set_client = @saved_cs_client */;

DROP TABLE IF EXISTS `actor`;

/*!40101 SET @saved_cs_client = @@character_set_client */;

/*!40101 SET character_set_client = utf8 */;

CREATE TABLE `actor` (

`actor_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,

`first_name` varchar(45) NOT NULL,

`last_name` varchar(45) NOT NULL,

`last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,

PRIMARY KEY (`actor_id`),

KEY `idx_actor_last_name` (`last_name`)

) ENGINE=InnoDB AUTO_INCREMENT=201 DEFAULT CHARSET=utf8;

/*!40101 SET character_set_client = @saved_cs_client */;

If there were no subsequent CREATE TABLE the recovery would be trivial. Index_id of the PRIMARY index of [...]

Filed Under: MySQL Tagged With: drop table, InnoDB, Recovery

Benchmarking Percona Server TokuDB vs InnoDB

More on MySQL transaction descriptors optimization

How to recover table structure from InnoDB dictionary

Repair MySQL 5.6 GTID replication by injecting empty transactions

InnoDB Full-text Search in MySQL 5.6 (part 1)

Feature preview: Compact backups in Percona XtraBackup

Logging Deadlock errors

When is MIN(DATE) != MIN(DATE) ?

Full Text Search Webinar Questions Followup

Recovery after DROP & CREATE

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