…#635399. (Yasufumi Kinoshita) Old variable use_global_long_query_time was deleted. (Oleg Tsarev) Bug…Yasufumi Kinoshita) Old variable enable_query_response_time_stats was renamed to query_response_time_stats. (Oleg Tsarev)…. (Yasufumi Kinoshita) The XtraDB version was set to 20.0. (Aleksandr Kuzminsky…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… of individual queries in this post, but instead intended to focus only on the overall response time for answering all of the queries in… Benchmark – Scale Factor 1 – Mysql 5.5 vs 5.6 response times are in seconds (lower is better) Version Buffer Cold Run1… row in set (0.00 sec) Now compare the difference with innodb_old_blocks_time=0; mysql> set global innodb_old_blocks_time=0; Query OK…
Post: The Optimization That (Often) Isn't: Index Merge Intersection
December 14, 2012 By 6 Comments
…query on the server by two orders of magnitude. Other queries were running maybe 1000 or 2000 times, but this one? # Rank Query ID Response time… configuration setting and disable index_merge_intersection. It’s a dynamically-adjustable setting and can be modified globally or per-session: SET [GLOBAL|…
Post: Percona Server 5.1.53-12.4
December 29, 2010 By Leave a Comment
…response_time_distribution and compile option –without-response_time_distribution in Response Time Distribution. (Oleg Tsarev) Bugs Fixed Bug #643149 – Slow query…, slow_query_log_microseconds_timestamp, use_global_long_query_time. (Oleg Tsarev…Tsarev) Bug #676158 – Setting the query cache size to…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 28 Comments
…in terms of counters you can get from SHOW GLOBAL STATUS. I’ll start out by copying and …standpoint of response time measurements, which you should, you will eventually arrive at this question. “I have a query I …it as a heuristic for how big your working set is. Set the key_buffer_size to that. If …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… short queries, this can be a non-trivial part of the app’s response time. …, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+… don’t spend a lot of time on settings and status. It is not…
Post: More on dangers of the caches
September 23, 2010 By 5 Comments
… MySQL was getting overloaded with thousands of same queries… which corresponded to cache miss storm but …so we did it on MySQL side instead. “SET GLOBAL max_connections=20″ to limit number of …some cases when cold performance gives too bad response time you may want to prime the caches by…
Post: Sell-an-Elephant-to-your-Boss-HOWTO
August 28, 2012 By 3 Comments
… we are working on in the global picture and what not. 2. …still due to queueing response time would be unstable during peak times. For every 60 … go to your manager or whoever sets project priorities and make it clear:…to better hardware, optimizing indexes or queries, tuning MySQL etc. which we can…
Post: Data compression in InnoDB for text and blob fields
May 30, 2012 By 2 Comments
…utilized TEXT fields with some read queries exceeding 500MB (!!), and stored in a…table were over 8KB, which were responsible for 90% of space usage …_SIZE as we had minimal time to effect the table compression modification…don’t forget to set it in my.cnf!): SET GLOBAL innodb_file_format=BARRACUDA;…
Post: Living with backups
November 6, 2008 By 28 Comments
…the regular database activities, which need fast response times, and doing backups which would gladly act… To check what is the current setting you need to query your block devices. In case…was_running= 1; } … my $sth= $dbh->prepare(‘SHOW GLOBAL STATUS LIKE “Threads_connected”‘); … if ($$row[1] < …
