…in software RAID 10. Now let’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5…reduce contention problems caused by buffer pool mutexes, using “estimate” checkpoint method to reduce…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…result in a lot of Random I/O. The purpose of MRR is to reduce…in MariaDB 5.5 and not in MySQL 5.6, is that because of a bug in MySQL 5.6 code? As MRR was used in both MySQL 5.6 and MariaDB 5.5…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…reducing table cache reduces memory consumption to be withing the reason. Connection Related Allocations Another set…Memory Leaks There are many kinds of memory leaks and I would say these are rather rare in MySQL. Most suspected memory…
Post: MySQL Query Cache
July 27, 2006 By 69 Comments
…result set but MySQL…memory – Queries are constantly being invalidated from query cache by table updates, this means number of queries in cache and memory used…memory and Qcache_lowmem_prunes – If you’re not getting much of lowmem_prunes and free_memory stays high you can reduce…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
…reduced mutex contention. The performance improvements I got with Percona Server were similar to the performance improvements I saw versus stock MySQL 5…set of data (what we call the working set) to fit in the InnoDB buffer pool, which means you need it to fit in memory…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
…MySQL 5.5 uses for Innodb Buffer Pool and have multiple MySQL Query Cache instances hashed by query hash. It would help to reduce…Results sets for most queries is highly compressible and light compression can compress results…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…in MySQL 5.1 Disk Space For MyISAM tables hosting providers used to use disk quotas for MyISAM tables. You can also use…memory can stored procedure allocate ? say can you create 1000 variables in stored procedure and set 1M result set…
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
…Memory…MySQL versions or settings. Moreover, I have been running these benchmarks for a customer so I just used the setting that they would have used…reduced single-thread performance by 5-10%. Sequential write results…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…used for read ahead and results were significant. They however were not merged in…in MySQL 5…In high load situations where INNODB is using most of the system’s memory the kernel can decide (incorrectly) to swap out MySQL…used for buffer pool and which are not swappable. They also allow to reduce…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…reduce the gap but I doubt it will be closed. Joins Joins are used…sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL…in parallel and aggregate result sets. So if you’re dealing with large data sets…
