…definition can result in a lot of Random I/O. The purpose of MRR …combined size of the secondary key tuples fetched, and N is the buffer size. In MySQL…20920 23734 Innodb_buffer_pool_read_requests 1361851 1264739 1235472 1263290 1235781 …when MRR is used then there are two separate calls made to the …
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
…will test two workloads size…MySQL and we specially implemented bunch of tests to ease hardware evaluation for things which are important for MySQL…of random requests for random IO: 1000000 Read/Write ratio for combined random IO test: 1.50 Calling fsync() at the end of…expect this result while running…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… use combined memory and a lot of …to two full table scans (as 60mil of rows…MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests…of CPUs will not help. Sometimes it is good idea to manually split query into several, run in parallel and aggregate result…
Post: Review of Virident FlashMAX MLC cards
November 10, 2011 By 14 Comments
… request, I performed an evaluation of their MLC card to assess how it handles MySQL workload. As I am very satisfied with the results…, sysbench v5 Of course, our Percona Server was optimized for Flash cards, with variations for two settings. I tested combinations of innodb_buffer_pool…
Post: Innodb row size limitation
April 7, 2011 By 11 Comments
… data into it: mysql> INSERT INTO example -> VALUES ( …consequence of InnoDB storing two …result of the COMPRESS function is always binary, so for example, you should use a BLOB instead of…requested as part of a row-read, they don’t have to be touched at all. Of course, these approaches can be combined…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
…of posts showing benchmark results on Amazon EC2 servers with RAID’ed EBS volumes and MySQL… of these two approaches to hosting MySQL in the Amazon cloud. In general, MySQL… severe stalls as I/O requests stack up and other things block….1′s performance with the combination of stock MySQL 5.1, EC2, and …
Post: How Percona Develops Open-Source Software
January 9, 2009 By 4 Comments
… so forth. We notice these requests, and if they come …of our business. I’ll clarify that in a minute. There are generally two…, and Sun/MySQL will be reselling the results. This is …combine these things when we can! The complexity of our customers’ different situations leads to the need for a lot of…
