…to be slower than tables with short rows. I was interested to check… ) ENGINE=…on…mysql [localhost] {msandbox} (test) > explain select max(t1+0) from t99v1; +—-+————-+——-+——-+—————+——+———+——+———-+————-+ | id | select_type | table | type…to how…
Post: Connecting orphaned .ibd files
May 13, 2011 By 19 Comments
…ENGINE=InnoDB DEFAULT CHARSET=latin1 Please note field SPACE. For table actor it is equal to 15: mysql> select…TYPE 2 current defined types…To refrain from such error ibdconnect does check if the space_id is already used. It will refuse to…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…on multiple CPU systems you need some spinning done, at least for some types…to see how small indexes really are. [-] No “using index” Falcon always have to check…MySQL Storage Engine level for MySQL – reading rows in their physical order can be applied to most storage engines…support for SELECT FOR …
Post: Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
…) ENGINE=MyISAM DEFAULT CHARSET=utf8 mysql> select…on t1.i=t2.j \G *************************** 1. row *************************** id: 1 select_type: SIMPLE table: t1 type…to 3.5 seconds which is just 20% slower than integer based join for Innodb. Finally I decided to check…to integer based join. So how…
Post: Find and remove duplicate indexes
June 20, 2012 By 9 Comments
…MySQL needs to examine more query plans. The storage engine needs to…to explain the different types of duplicate indexes and how to find and remove them. Duplicate keys on…SELECT * FROM t WHERE name=’kahxailo’ AND i > 100000; With a index on…
Post: MySQL 6.0 vs 5.1 in TPC-H queries
March 25, 2008 By 17 Comments
…ENGINE=MyISAM DEFAULT CHARSET=latin1 with 59986052 rows So this query takes 32.27 sec to…select_type | table | type…to 1200 finally. Probably we need to check how really MRR works. What else worth to mention here is that MySQL…
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
…MySQL 5.1 get MySQL slow query log logged in mysql…to change table to other storage engine…to get new queries in the end you can do SELECT * FROM (SELECT…to MyISAM, disable concurrent inserts and run long reporting query on the log file query execution is still proceeds. I have not checked…
Post: Hijacking Innodb Foreign Keys
January 2, 2012 By 2 Comments
…on rename of ‘./test/child’ to ‘./test/#sql2-496-40a5′ (errno: 152)” in many cases and foreign keys are still handled on storage engine…mysql> set foreign_key_checks=1; Query OK, 0 rows affected (0.00 sec) mysql> select…how to…
Post: Logging Deadlock errors
September 19, 2012 By 4 Comments
…ENGINE INNODB STATUS and log the new deadlocks to a file or to a table that we can later review. Let’s see how…check the deadlock information in our table: mysql> select…_type…on every node and configure it to store logs on a centralized database. In MySQL 5.6 will be possible to log all deadlocks on…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… you want but not how to get it. Most distributed engines work with rows. They …to distribute work over any type of compute resource which speaks SQL, but right now only MySQL…selected for a UNIQUE CHECK * on the base table: `origin_airport_id` * storage node result set merge optimization enabled: ON…
