by Yves Trudeau | Jun 8, 2015 | Insight for DBAs, MySQL, Percona Software
Ever since MySQL replication has existed, people have dreamed of a good solution to automatically split read from write operations, sending the writes to the MySQL master and load balancing the reads over a set of MySQL slaves. While if at first it seems easy to...
by Stephane Combaudon | Jun 3, 2015 | Insight for DBAs, MySQL, Percona Software
Some applications have a heavy write workload on a few records – for instance when incrementing a global counter: this is called a write hotspot. Because you cannot update the same row simultaneously from multiple threads, this can lead to performance...
by Jay Janssen | Jun 2, 2015 | Insight for DBAs, MySQL
It seems these days if anyone knows anything about tuning InnoDB, it’s that you MUST tune your innodb_buffer_pool_size to 80% of your physical memory. This is such prolific tuning advice, it seems ingrained in many a DBA’s minds. The MySQL manual to this...
by Robert Barabas | Jun 1, 2015 | Insight for DBAs, MySQL
I thought it was worth a moment to reiterate on the new Performance Schema related defaults that MySQL 5.7.7 brings to the table, for various reasons. For one, most of you might have noticed that profiling was marked as deprecated in MySQL 5.6.7. So it is expected...
by Muhammad Irfan | May 27, 2015 | MySQL, Percona Services
The other day I was discussing new features of MySQL 5.7 with a Percona Support customer. After that conversation, I thought it would be a good idea to compile list of important features of MySQL 5.7. The latest MySQL 5.7.6 release candidate (RC) is out and is packed...
by Roel Van de Paar | May 15, 2015 | Insight for DBAs, Insight for Developers, MySQL, Percona Services, Percona Software
Welcome to MySQL QA Episode 2: Build a MySQL Server – Git, Bazaar (bzr), Compiling, and Build Tools In this episode you’ll learn how to build Percona Server and/or MySQL Server for QA purposes & more in this short 25 minute tutorial. In HD quality (set...
by Stephane Combaudon | May 8, 2015 | Insight for DBAs, MySQL
We discussed in an earlier post how to design indexes for many types of queries using a single table. Here is a real-world example of the challenges you will face when trying to optimize queries: two similar queries, but one is performing a full table scan while the...
by Stephane Combaudon | May 5, 2015 | MySQL
Being schemaless is one of the key features of MongoDB. On the bright side this allows developers to easily modify the schema of their collections without waiting for the database to be ready to accept a new schema. However schemaless is not free and one of the...
by Francisco Bordenave | May 4, 2015 | Insight for DBAs, MariaDB, MySQL
MySQL replication isn’t perfect and sometimes our data gets out of sync, either by a failure in replication or human intervention. We are all familiar with Percona Toolkit’s pt-table-checksum and pt-table-sync to help us check and fix data inconsistencies...
by Vadim Tkachenko | May 1, 2015 | Benchmarks, MySQL
An idea for a benchmark based on the “arrival request” rate that I wrote about in a post headlined “Introducing new type of benchmark” back in 2012 was implemented in Sysbench. However, Sysbench provides only a simple workload, so to be able to...
by Sveta Smirnova | Apr 30, 2015 | Insight for DBAs, MySQL, Percona Live
In version MySQL 5.7.7 Oracle presented a new promising feature: optimizer hints. However it did not publish any documentation about the hints. The only note which I found in the user manual about the hints is: It is now possible to provide hints to the optimizer by...
by Alexander Rubin | Apr 29, 2015 | MySQL
About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns. The...
by Stephane Combaudon | Apr 28, 2015 | Insight for DBAs, MySQL, Percona Software
I often talk with people who are very interested in the features of Percona XtraDB Cluster (PXC) such as synchronous and parallel replication, multi-node writing and high availability. However some get confused when operating a real PXC cluster because they do not...
by Stephane Combaudon | Apr 27, 2015 | Insight for DBAs, MySQL
I have recently seen several cases when performance for MySQL queries on a single table was terrible. The reason was simple: the wrong indexes were added and so the execution plan was poor. Here are guidelines to help you optimize various kinds of single-table...
by Peter Zaitsev | Apr 21, 2015 | Insight for DBAs, MySQL, Webinars
MySQL sharding is one of the most used and surely the most abused MySQL scaling technology. My April 2 Dzone article, “To Shard, or Not to Shard,” proved there is indeed quite an interest in this topic. As such, I’m hosting a live webinar tomorrow...
by Jervin Real | Apr 16, 2015 | MySQL
When optimizing queries and investigating performance issues, MySQL comes with built in support for profiling queries aka SET profiling = 1; . This is already awesome and simple to use, but why the PERFORMANCE_SCHEMA alternative? Because profiling will be removed soon...
by Miguel Angel Nieto | Apr 15, 2015 | MySQL
Data inconsistencies in replication environments are a pretty common. There are lots of posts that explain how to fix those using pt-table-checksum and pt-table-sync. Usually we only care about the data but from time to time we receive this question in support: How...
by Jervin Real | Apr 10, 2015 | Benchmarks, MySQL, Percona Software
A few years back Deva wrote about how to use tcpdump on very busy hosts. That post sparked my interest about exploring how to measure the impact of tcpdump on very busy hosts. In this post, I wanted to highlight how much of an impact there really is and what options...
by Nilnandan Joshi | Apr 9, 2015 | MySQL, Percona Live
Recently, I was working on one of the issue related to locks and deadlocks with InnoDB tables and I found very interesting details about how InnoDB locks and deadlocks works with or without index for different Isolation levels. Here, I would like to describe a small...
by Valerii Kravchuk | Apr 7, 2015 | Insight for DBAs, Insight for Developers, MySQL, Percona Live, Percona Services
Two years ago Ovais Tariq had explained in detail what kinds of problems existed before MySQL introduced metadata locks in 5.5.3 and how these locks help to prevent them. Still, some implications of metadata locking in MySQL remain unclear for users – DBAs and...
