May 19, 2013

Feature preview: Compact backups in Percona XtraBackup

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 [...]

MySQL Indexing Best Practices: Webinar Questions Followup

I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others are better answered in writing anyway. Q: One developer on our team wants to replace longish (25-30) indexed varchars with [...]

Improved InnoDB fast index creation

One of the serious limitations in the fast index creation feature introduced in the InnoDB plugin is that it only works when indexes are explicitly created using ALTER TABLE or CREATE INDEX. Peter has already blogged about it before, here I’ll just briefly reiterate other cases that might benefit from that feature: when ALTER TABLE [...]

How network can impact MySQL Operations ?

This week I’ve worked with the customer doing certain work during maintenance window which involved a lot of data copying around between MySQL boxes. We had prepared well and had measured how fast we could copy the data between servers of these kind connected to the same network, and we did the same thing before. [...]

Tools

This page contains links to various tools we found helpful to use in practice. Some tools are written by us, others by third parties, yet another ones may be shipped with your operating system you just need to find they are there. Percona Toolkit Percona Toolkit is a great set of tools for MySQL Performance [...]

Quickly preloading Innodb tables in the buffer pool

In the previous post I mentioned a way I use to preload Clustered Index (data) for Innodb tables. Though I thought this topic would benefit from a bit more information. But lest first start with feature request for Innodb Team: All ways I mention here are hacks and they can’t be as efficient as native [...]

Learning about MySQL Table Fragmentation

Recently I was working with the customer who need quick warmup – to get Innodb table fetched in memory as fast as possible to get good in memory access performance. To do it I run the query: “SELECT count(*) FROM tbl WHERE non_idx_col=0″ I use this particular form of query because it will do full [...]

How multiple disks can benefit for single client workload ?

Let us talk few more about disks. You might have read my previous post and Matt’s Reply and it looks like there are few more things to clarify and explain. Before I get to main topic of the article lets comment on IO vs Disk question. If you look at Disk Based databases all data [...]

Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also [...]

Read Buffers, mmap, malloc and MySQL Performance

Monty Taylor posted interesting investigation of the fact read_buffer_size variable affects connection speed. This is not something you would expect right ? me too. Not only global user data is expected to be cached on startup but even if it is not why would you do full table scan to fetch single user information ? [...]