… a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars. If you missed it, you can…simplify the development of a report, but whether it’s a benefit to performance is a case-by-…` by a secondary index. But the result was that it created a temporary table to count the movies…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query-log-stdin –dispatcher-plugin thread-pool –thread-pool-threads-count 100 –session-init-query…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…a followup by Dimitri Kravchuk, we have received a large number of questions on why the benchmark results…single SELECT queries doing PRIMARY KEY lookups (aka QPS sysbench mode); same MySQL queries executed inside single…1..1024> –test=oltp.lua –oltp_tables_count=8 –oltp-table-size=1000000 –rand-…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…a hypothesis. vCache vs. FlashCache – dirty page threshold Finally, we examine the impact of a couple of…results were obtained with the default vCache configuration, I think vCache can be declared the clear winner. Base MySQL… max_prepared_stmt_count=500000 max_…1000 query_cache_size = 0 query_cache_…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…a drop, and by end of 5 hours the average throughput is 7800 tps. Something to take into account: TokuDB results…oltp-table-size=10000 –mysql-user=root –oltp-tables-count=32 –mysql_table_engine=tokudb –oltp_auto… 4M thread_cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft_min_word_len…
Post: Fun with the MySQL pager command
January 21, 2013 By 6 Comments
…result of a command spanning over many lines (for instance SHOW ENGINE INNODB STATUS): mysql> pager less PAGER set to ‘less’ mysql…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
… the view is refreshed. This is similar to storing the results of a query in Memcache. When the cache “expires”, the contents must be… to calculate the number of lines in the order_lines table, three orders of magnitude more quickly than COUNT(*). mysql> select count(*) cnt from order…
Post: How to find MySQL queries worth optimizing ?
September 11, 2012 By 6 Comments
… to examine 10Mil rows to produce result. What would be good scenario ? – query examining same amount of rows as they end up sending… top level MySQL part for processing are counted the Rows_examined remains zero. It looks simple so far but it also a huge… to the tables is “const” MySQL does not count it as access to two tables. In case of “real” access to the data…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
…))`,COUNT(*) AS `count(*)` FROM words2 AS `words2` GROUP BY 1,2,3 ORDER BY NULL ) The other important optimization combines results from multiple queries… degree of parallelism that this data set can achieve with my method. Likely current network technologies can not support such a degree. mysql…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…a result set? This isn’t really a trick question. The “result set” is a SET created by the output of a…a plan for a simple query with aggregation, a JOIN, and a WHERE clause that uses an IN clause: — INPUT SQL: select origin_airport_id, count…
