June 20, 2013

Post: MySQL Query Patterns, Optimized - Webinar questions followup

June 3, 2013 By 2 Comments

… interim result set, and then …values against multiple columns in a compound index, then the order would matter, and it would have to match the order of columns in…in this case to force MySQL to scan the `title` table first, grouping by kind_id in… you find unexpected differences in performance like…

Filed Under: Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

… to DROP multiple FT indexes with InnoDB in the same…| +———————-+———-+———-+———-+ 1 row in set (4.60 sec) mysql> select * from information_schema.innodb_ft_config; +—————————+———+ | KEY | VALUE | … do find that the number of rows in I_…

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Post: MySQL Users Conference - Innodb

May 9, 2007 By 6 Comments

… pages do we have in the index with current compression settings. The same utility could…statement level MySQL Replication which among other requirements, needs all auto-increment values in multiple value insert …value allocated, some may already have values specified. I’m not sure if Heikki will find…

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Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

…MySQL 5.5.30 and testing multiple buffer pools on MySQL 5.5.30. Finally, MySQL…in set (0.00 sec) mysql> select * from information_schema.global_status where variable_name like ‘%innodb%read%’; +—————————————+—————-+ | VARIABLE_NAME | VARIABLE_VALUE…

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Post: Why MySQL could be slow with large tables ?

June 9, 2006 By 141 Comments

…mysql> select count(pad) from large; +————+ | count(pad) | +————+ | 31457280 | +————+ 1 row in set (4 min 58.63 sec) mysql…values first and then accessing rows in… finding …multiple servers to host portions of data set. Store portion of data you’re going to work with in…

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Post: Edge-case behavior of INSERT...ODKU

October 27, 2012 By 6 Comments

…MySQL checks our INSERT, sees that the next auto-inc value…in set (0.00 sec) (root@localhost) [test]> INSERT INTO update_test (username, host_id) VALUES…multiple unique indexes such as this one would be equivalent to “UPDATE update_test SET…

Filed Under: Insight for DBAs, Insight for Developers, MySQL

Post: MySQL Connection Timeouts

April 19, 2011 By 4 Comments

… the case by running netstat -s and finding something like: 38409 times the listen queue …- is MySQL parameter back_log which has default value of just 50. You may want to set it …From this point on MySQL processes network communication in multiple threads and can benefit from multiple cores but this …

Filed Under: Insight for DBAs, MySQL

Post: MySQL: what read_buffer_size value is optimal ?

September 17, 2007 By 25 Comments

…set this variable to some high value. Sample my.cnf values on large memory sizes recommend 1M settings and MySQL built-in…MySQL 5.1.21-beta was used for tests. mysql> select count(*) from dt2 where slack like “a%”; +———-+ | count(*) | +———-+ | 4705992 | +———-+ 1 row in set…multiple…

Filed Under: Benchmarks, Insight for DBAs Tagged With:

Post: Shard-Query EC2 images available

May 11, 2011 By 2 Comments

… instances. MySQL will fail to start on a micro instance, simply decrease the values in …null 2>&1 < /dev/null done; Where to find the images Amazon ID Name Arch… and/or loading among multiple nodes as well. Note that in the demonstration each… from 1988 to 2010 1 row in set (0.00 sec) With ICE, after…

Filed Under: MySQL

Post: Load management Techniques for MySQL

May 6, 2012 By 3 Comments

… with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out what the… not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing these does help in many… too high Many developers will test script with multiple level of concurrency and find out doing work from 32 processes is faster…

Filed Under: Insight for DBAs, MySQL
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