…for this workload are: $ID=monotonically increasing ID $K=rand(0,10000) // … performs if PK is (`id`,`hid`,`mid`). This also will affect select performance…myisam_max_sort_file_size = 10G #myisam_max_extra_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover socket=/var/lib/mysql/mysql…
Post: MySQL Crash Recovery
July 30, 2006 By 30 Comments
… care of or which may seriously affect MySQL Performance. MyISAM Corruption – If you’re writting to MyISAM tables there is very large chance of… may reduce performance dramatically. So if you’re bringing server back after crash you might want to populate caches. For MyISAM key… only some users initially (returning error to others) and gradually increase the load as server warms up. This may sound strange…
Post: MySQL Performance on Memory Appliance
March 31, 2008 By 23 Comments
… out MySQL Performance on “Memory Appliance” …performance IO subsystem. But not only performance was poor with single thread it also did not scale well with increased…MyISAM with myisam_use_mmap option which did not seems to give any significant performance benefit, may be even reducing performance…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
…MySQL DBAs or be involved with MySQL Performance in some way is to ask them what should be tuned in MySQL… more sensitive to buffer size compared to MyISAM. MyISAM may work kind of OK with default …for large data sets. Larger sizes offer better performance but increase recovery times so be careful. I …
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | PERFORMANCE_SCHEMA_MAX_COND_INSTANCES | 1000 | 836 | | PERFORMANCE…MySQL 5.6 with default configuration back_log Minor increase…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… is appended to it internally anyway. For MyISAM table you should use K(id2,id1)… really should worry about performance impact of extending index is when you increase its length dramatically,… 5″ and “`id` IN (5)” regarding indexes and performance? A: Recent MySQL versions are smart enough to convert …
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
…performance improvement you see your performance being worse. What should you do ? First if you followed MySQL… such as innodb-stats-method and myisam-stats-method. For Innodb storage engines…increasing innodb-stats-sample-pages to get more accurate results. In recent Percona Server versions and MySQL…
Post: MySQL: what read_buffer_size value is optimal ?
September 17, 2007 By 25 Comments
… work with MySQL Performance Optimization and Optimization for other applications the better … NOT NULL, `slack` varchar(50) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 1 row in set (0…results look really strange. Performance indeed grows by few percent as you increase buffer to 128K but after…
Post: Wow. My 6 year old MySQL Bug is finally fixed in MySQL 5.6
August 30, 2012 By 2 Comments
…perform match of constant which is too large to the column instead of simply responding with empty set MySQL truncates the constant, performs… KEY `i` (`i`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 mysql> select i,count(*) cnt… for values over 2bil becoming increasingly more expensive. Because there would…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… small queries might only barely increase memory consumption for given thread, however if table will perform complex operations such as full table… CREATE TABLE privilege should be able to run MySQL server out of memory MyISAM buffers. MyISAM may allocate buffer which is large enough…
