June 19, 2013

Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency

May 22, 2013 By Leave a Comment

… optimize queries for a star schema. A star schema presents some unique challenge to the database optimizer. …is important to note that in all cases, lower times are better. SSB Flight #1 Here …=/mnt/mysql56/data basedir=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user=justin innodb_buffer_pool_…

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Post: Choosing a MySQL HA Solution - Post-Webinar Q&A

June 7, 2013 By Leave a Comment

…with a virtual-machine approach, but for the optimal production deployment you want two identical physical boxes…binary log data being sent down to the lower-level slaves. You can also use the slave…query, but it’s always possible to build something more involved if that’s what you need. Q: What MySQL…

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

Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2

April 12, 2013 By 3 Comments

… lower isolation levels it is created for each SELECT, even within the same transaction. Why is that a major problem for MySQL…-only server nor rewriting application queries. Furthermore, it can be combined with the read-only optimization in MySQL 5.6 to achieve even….e. all queries are single-statement SELECT statements in autocommit. Which is the perfect case for read-only optimization in MySQL 5.6…

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Post: Is MySQL 5.6 slower than MySQL 5.5?

February 18, 2013 By 23 Comments

… – MySQL 5.6 Optimizer got a lot smarter and the more plans have to be considered for the query the more time the query optimization… comes from Performance Schema ? Whenever we get difference higher or lower with high concurrency compared to single thread ? Note Sysbench is… advantage of any of new MySQL 5.6 optimizations so it is geared towards worse case scenario for MySQL 5.6 performance. Here…

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Post: Ultimate MySQL variable and status reference list

January 8, 2011 By 4 Comments

…amazing MySQL manual, especially the option and …query_timeblogpercona.commanual low_priority_updatesblogpercona.commanual lower_case_file_systemblogpercona.commanual lower….commanual optimizer_prune_levelblogpercona.commanual optimizer_search_depthblogpercona.commanual optimizer_switchblogpercona….

Filed Under: Insight for DBAs, MySQL

Post: MySQL 5.5 and MySQL 5.6 default variable values differences

February 21, 2013 By 8 Comments

…from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query: mysql [localhost] {…445 tables and 224 threads in this case, lower than 5.5 values. Though it makes …my opinion. MySQL 5.6 adds a lot more optimizer switches which you can play with: mysql [localhost] {msandbox} (test…

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Post: Distributed Set Processing with Shard-Query

May 14, 2011 By 27 Comments

… incremental materialized view optimizations can be applied. Shard-Query works only on sets Shard-Query takes relational … which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law…results from the slowest node will place a lower bound on the minimum performance level. Soon …

Filed Under: MySQL

Post: A micro-benchmark of stored routines in MySQL

August 16, 2009 By 7 Comments

… where lower(cl.Language) = ‘English’ and co.Code = c; > return res; > end// mysql> delimiter ; Now the query can be rewritten as this: mysql> select… apples and uhm, apples… please comment). The poorly-optimized-subquery portion of the query essentially happens inside that function now. And it…

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Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5

March 21, 2012 By 10 Comments

… can be. This is also evident in the query times, which is lower by a couple of seconds when buffer size of… during cold query runs the optimizer would switch to using plan ‘a’, which does not involve MRR, and the query time for MySQL 5… in query times between MySQL 5.5 and MySQL 5.6/MariaDB 5.5 This is another area of improvement in the optimizer, as…

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

February 26, 2013 By 1 Comment

… (I may be one of the few people that likes lower_case_table_names = 1 in /etc/my.cnf), but I…_test_innodb’; mysql> set global innodb_optimize_fulltext_only=1; mysql> select * from information_schema.innodb_ft_config; +—————————+——–+ | KEY | VALUE | +—————————+——–+ | optimize_checkpoint_limit | 180… (0.00 sec) mysql> delete from dir_test_innodb LIMIT 200000; Query OK, 200000 rows affected (8.65 sec) mysql> optimize table dir_test…

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