MySQL server intensively uses dynamic memory allocation so a good choice of memory allocator is quite important for the proper utilization of CPU/RAM resources. Efficient memory allocator should help to improve scalability, increase throughput and keep memory footprint under the control. In this post I’m going to check impact of several memory allocators on the [...]
Find unused indexes
June 30, 2012 By Leave a Comment
I wrote one week ago about how to find duplicate indexes. This time we’ll learn how to find unused indexes to continue improving our schema and the overall performance. There are different possibilites and we’ll explore the two most common here. User Statistics from Percona Server and pt-index-usage. User Statistics User Statistics is an improvement [...]
DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during off-peak hours. But I have seen cases where the [...]
Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN
June 14, 2012 By 7 Comments
I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment. They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon). The ping RTT latency [...]
A case for MariaDB’s Hash Joins
May 31, 2012 By Leave a Comment
MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I will show the results of executing benchmarks [...]
Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
This is the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is targeted at the join related optimizations introduced in the optimizer. These optimizations are available in both MySQL 5.6 and MariaDB 5.5, and MariaDB 5.5 [...]
Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
This is the second blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is aimed at the optimizer enhancement Multi Range Read (MRR). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take a look at [...]
Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition Pushdown (ICP). Its available [...]
Introducing new type of benchmark
February 25, 2012 By 16 Comments
Traditionally the most benchmarks are focusing on throughput. We all get used to that, and in fact in our benchmarks, sysbench and tpcc-mysql, the final result is also represents the throughput (transactions per second in sysbench; NewOrder transactions Per Minute in tpcc-mysql). However, like Mark Callaghan mentioned in comments, response time is way more important [...]
MySQL Configuration Wizard Updated
January 26, 2012 By 5 Comments
We’ve released an updated version of the MySQL Configuration Wizard we announced at the end of last year. If you don’t remember that announcement, here’s the short version: this is a tool to help you generate my.cnf files based on your server’s hardware and other characteristics. We’ve gotten really good feedback on this tool, including [...]
