June 19, 2013

Post: How Percona does a MySQL Performance Audit

November 24, 2008 By 17 Comments

… be other ways to get this information, too. The last three commands …how to read these, there’s a full explanation in our book, High Performance MySQL…I run EXPLAIN if possible (rewriting non-SELECT queries if needed, and using … within which we have to deliver the maximum value to the customer. If we…

Filed Under: Insight for Developers Tagged With:

Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes

July 25, 2012 By 6 Comments

… how it needs to…to select a Primary Component, we have then a split-brain condition. In our 2 nodes setup when a node loses connection to…mysql> insert into percona values (0,’percona1′,’jaime’); Query OK, 1 row affected (0.02 sec) percona1 mysql> select…total), act_id = 19, last_appl. = -1, protocols…

Filed Under: MySQL, XtraDB Cluster

Post: Can MySQL temporary tables be made safe for statement-based replication?

May 26, 2008 By 8 Comments

…about how to make MySQL replication reliable, part of which is to eliminate temporary …Last_Errno: 1146 Last_Error: Error ‘Table ‘test.t’ doesn’t exist’ on query. Default database: ”. Query: ‘insert into test.t(a) values… into test.t(a) values(1); -> insert into test.ins(a) select * from test.t;…

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Post: InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

March 4, 2013 By 7 Comments

…To test this hypothesis, I reset innodb_ft_min_token_size to 1, dropped/rebuilt the InnoDB index, and tried again. mysql: SELECT… implications to cranking this value all …last point bears particular emphasis, as it also illustrates an important best practice even if FTS isn’t involved. Always test how…

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Post: Statement based replication with Stored Functions, Triggers and Events

December 16, 2011 By 4 Comments

…’ll learn what problems can we have and how to avoid them. TRIGGERS When a statement activates… the slave. Example: mysql> SELECT YEAR(CURDATE()) INTO @this_year; mysql> insert into t VALUES(@this_year) Binary Log… INTO y (value) VALUES(1) If we use “LAST_INSERT_ID” on our master the value of that…

Filed Under: MySQL

Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5

April 4, 2012 By 4 Comments

… the selected rows are read from table1, the values of indexed columns that will be used to perform a…10; In-memory workload Now let’s see how effective are the join optimizations when the …compared to MySQL 5.6. Next interesting thing are the last two columns of the table above and the values …

Filed Under: Benchmarks, Insight for DBAs, MySQL Tagged With: , , , , , , , , , , , , , ,

Post: High-Performance Click Analysis with MySQL

December 22, 2008 By 13 Comments

…to measure the ad’s value?  Is it enough to know how…) provides real-time reporting last time I was …MySQL, you’re going to end up heavily I/O bound.  Listen to any of the talks at past MySQL…to think about how to avoid enormous tables that are hard to… INSERT..SELECT queries, it will propagate to the…

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Post: MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown

March 14, 2013 By 2 Comments

… “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5… actually very different from the “rows” value seen above. This is because the…last GA release? Then I invite you to join me at the webinar I have prepared for this Friday, March 15: “Learn How MySQL…

Filed Under: Events and Announcements, Insight for Developers, MySQL Tagged With: , ,

Post: Replaying database load with Percona Playback

October 25, 2012 By 9 Comments

…I’m going to show how to meassure the impact …to the DEV server we can replay the load: percona-playback –mysql-host=127.0.0.1 –mysql-user=root –mysql… != expected 211 for query: SELECT DISTINCT ol_i_…we can go further. Last change, flush logs … to the original value :) This is an easy example of how…

Filed Under: Insight for DBAs, MySQL

Post: Recovery deleted ibdata1

August 10, 2012 By 9 Comments

…values…to 363096003 Last checkpoint at 363096003 Max checkpoint age 7782360 To speed up flushing we can set dirty pages percentage to zero: mysql…mysql> select count(*) from sbtest; +———-+ | count(*) | +———-+ | 1000000 | +———-+ 1 row in set (0.19 sec) Conclusions Add to…

Filed Under: Insight for DBAs, MySQL Tagged With:
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