…execution time of 30 seconds exceeded in /var/www/html/tightloop.php on line 5″ just as expected. For rest of…MySQL queries this would be counted to max_execution_time…
Post: Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
…of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of…_blocks_time = 1000 …set max_connections to over 5000 or use more than 5000 tables. There is also little “savings” in…set this variable to higher values for sessions executing complicated queries. I think this piece of…
Post: Talking MySQL to Sphinx
April 19, 2009 By 4 Comments
…set even if you have not asked it. Another thing to try is GROUP BY – Sphinx executes GROUP BY in… | +————+——–+———-+———–+———+ 10 rows in set (32.47 sec) MySQL mysql> select max…MySQL these days. Now on performance – for given class of queries Sphinx was just 1.5-2 times…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
…execution time, and parse time, respectively. Actually performance is a little worse. This is not unexpected. Since Shard-Query must add at small amount of…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…mysql> use ontime1; Database changed mysql…in our query response times and throughput. Setting up a cluster using the AMI images You can easily test Shard-Query…Execute the test: As seen above, the run_query script will run one more more semicolon terminated SQL statements. The queries…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…of subtables will likely cause your MySQL server to run out of file descriptors. The same is true for Partitioned tables in MySQL…query is internally presented using parse tree inside MySQL which of course depends on query size which is controlled by max_allowed_packet. However some MySQL…
Post: Impact of logging on MySQL’s performance
February 10, 2009 By 8 Comments
…queries with execution time bigger than a second without worry about performance impact in case of CPU-bound workload. The performance impact is negligibly small in…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
… memory consumption by MySQL Server in given configuration….query executions Query Parsing and optimization needs memory. This is usually small to be ignored but certain queries…sets from remove queries. Blobs may require 3x time of memory. This is important if you’re deaing with large Blobs (your max…
Post: Gathering queries from a server with Maatkit and tcpdump
July 1, 2009 By 23 Comments
…of information about queries that mysql-proxy can, making this a viable way to monitor servers without the disadvantages of a proxy. In…query took a tenth of a second to execute…Query_time distribution … snip … show databases\G I did not know that SHOW DATABASES sets…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… and large myisam_max_sort_file_size…execution, if you run UPDATE which updates 1000000 rows after crash only 500000 of… at the time. Happily inserts in MyISAM are …of such queries to get into trouble. Just one is enough. Lock priorities. By default MySQL… with queries failing to run, wrong result sets …
