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Search Results for: auto increment field innodb

Comparing MongoDB, MySQL, and TokuMX Data Layout

A lot is said about the differences in the data between MySQL and MongoDB. Things such as “MongoDB is document based”, “MySQL is relational”, “InnoDB has a clustering key”, etc.. Some may wonder how TokuDB, …


Recovering temporal types in MySQL 5.6: TIME, TIMESTAMP and DATETIME

MySQL 5.6 introduces a new feature – microseconds resolution in some temporal types. As of 5.6.4 TIME, TIMESTAMP and DATETIME can have a fractional part. To create a field with subseconds you can specify precision …


Schema changes – what’s new in MySQL 5.6?

Among many of the improvements you can enjoy in MySQL 5.6, there is one that addresses a huge operational problem that most DBAs and System Administrators encounter in their life: schema changes. While it is …


Understanding the maximum number of columns in a MySQL table

This post was initially going to be two sets of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on, …


MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown

While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” …


Adventures in archiving

One of our Remote DBA service clients recently had an issue with size on disk for a particular table; in short this table was some 25 million rows of application audit data with an on …


Announcing Percona Server 5.1.66-14.2

Percona is glad to announce the release of Percona Server 5.1.66-14.2 on January 15th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.66, including all the bug fixes in it, Percona Server 5.1.66-14.2 is now the current …


Announcing Percona Server 5.5.28-29.3

Percona is glad to announce the release of Percona Server 5.5.28-29.3 on January 8th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.3 is now the current …


The Optimization That (Often) Isn’t: Index Merge Intersection

Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on …


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

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 …