Search Results for: index kind mysql

The small improvements of MySQL 5.6: Duplicate Index Detection

Here at the MySQL Performance Blog, we’ve been discussing the several new features that MySQL 5.6 brought: GTID-based replication, InnoDB Fulltext, Memcached integration, a more complete performance schema, online DDL and several other InnoDB and query optimizer improvements. However, I plan to focus on a series of posts on the small but handy improvements – […]

InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

This is part 2 in a 3 part series. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result sets. Our hope is that the one of two things […]

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

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 […]

Percona Live MySQL Conference and Expo 2013: The talks I want to see

I’ve been woefully neglectful of my responsibilities to post regularly about Percona Live MySQL Conference and Expo 2013 (PLCME 2013), but here’s some highlights of what I am planning to attend from the schedule.  Read to the very bottom for the chance to win a free full pass to the conference! When picking talks to attend, […]

Is there room for more MySQL IO Optimization?

I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL […]

Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd […]

Troubleshooting MySQL Memory Usage

One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other […]

Innodb vs MySQL index counts

I had a customer recently who a few strange errors in their mysqld.err log:

This customer was running Percona Server 5.1 and they got this error on two tables during a maintenance window when they were adding indexes to the same tables.  We had a suspicion that it had something to do with Fast […]