…, our VP of Consulting, will explain how to work with BigData effectively Justin Swanhart, our Senior MySQL Instructor, will continue the topic of BigData with a talk titled, “Conquering BigData with MySQL and Shard Query” Daniel Nichter…
Post: Experiences with the McAfee MySQL Audit Plugin
May 23, 2013 By 4 Comments
… you also need to do this, the details are clearly explained here. The plugin writes its output in json format, and…-sys-maint”,”host”:”localhost”,”cmd”:”Connect”,”query“:”Connect”} {“msg-type”:”activity”,”date”:”1369155747373″,”thread-id”:”6439″,”query-id”:”219309″,”user”:”debian-sys…”:”localhost”,”cmd”:”Connect”,”query“:”Connect”} In conclusion, the plugin API seems to be opening new possibilities of extending MySQL‘s behavior in…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
On Friday I gave a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars. If you missed it, you can still register… SQL can produce an infinite variety of queries. The query optimizer analyzes queries for common patterns the MySQL designers know can be improved. But… MySQL to scan the `title` table first, grouping by kind_id in index order. This made the first table in the EXPLAIN…
Post: The small improvements of MySQL 5.6: Duplicate Index Detection
May 31, 2013 By Leave a Comment
… like this in MySQL 5.5, you will succeed without errors or warnings: mysql> ALTER TABLE test ADD INDEX (col2); Query OK, 0… 2005!). The report explains more in detail what the “will be disallowed in a future release” means. In MySQL 5.7 the… on the query optimizer and the MySQL version, we always recommend to check manually the optimizations proposed by Percona Toolkit. The MySQL server…
Post: Rotating MySQL slow logs safely
April 18, 2013 By 7 Comments
…. Use the mysql console or mysqladmin utility to FLUSH LOGS; These options should be equivalent, but MySQL bug 65481 explains that the HUP signal also flushes tables in addition to logs. Flushing tables can impact running queries. Disable MySQL slow…
Post: Repair MySQL 5.6 GTID replication by injecting empty transactions
March 26, 2013 By 1 Comment
In a previous post I explained how to repair MySQL 5.6 GTID replication using two different methods. I didn’…: Error ‘Duplicate entry ’4′ for key ‘PRIMARY” on query. Default database: ‘test’. Query: ‘insert into t VALUES(NULL,’salazar’)’ Retrieved_Gtid_Set… is found in Percona Toolkit for MySQL. Last week I gave a talk at Percona MySQL University @Toronto about GTID. It includes…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… the first post: single SELECT queries doing PRIMARY KEY lookups (aka QPS sysbench mode); same MySQL queries executed inside single-statement transactions (TPS… was explained in the original post, but seems to cause much confusion. Even though the read-only transactions optimization in MySQL 5…
Comment: SimCity outages, traffic control and Thread Pool for MySQL
March 21, 2013 By 16 Comments
…5.5.x clusters with not just simple queries or simple transactions but high concurrency with complex…show just how far things have come with MySQL clustering performance: http://themattreid.com/wordpress/2013/03… as a package once I finish the articles explaining how it all works) As an aside, setting…
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
…as a part of query execution, sometimes being dynamic based on data. With EXPLAIN MySQL kind of simulates …rows will be examined MySQL will still print full number. Here is example: mysql> explain select * from lt limit 10; …
Post: MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
…, index condition pushdown. Let’s have a look at the EXPLAIN output: mysql> EXPLAIN SELECT * FROM cast_info WHERE role_id = 1 and… is available, this is always preferred over the ICP optimization: mysql> EXPLAIN SELECT role_id FROM cast_info WHERE role_id = 1…-party, independent and technical opinion about the new features of MySQL query planner? Are you not yet familiar with terms like MRR…
