June 19, 2013

Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency

May 22, 2013 By Leave a Comment

…a database‘s ability to optimize queries for a star schema. A star schema presents some unique challenge to the database…table. You can find the individual SSB query definitions in my previous blog post. Test environment These tests were done on a relatively fast machine with a…with no…

Filed Under: Benchmarks, MySQL Tagged With: , , , , , , ,

Post: More on MySQL transaction descriptors optimization

April 26, 2013 By Leave a Comment

…tables with 1M rows each (about 2.1GB) for his tests, while in our original tests we used a much larger one, 16 tables with 5M rows…a fully read-only server. As soon as there is a non-trivial amount of updates to the database, all SELECT queries, even those participating in…

Filed Under: Benchmarks, MySQL Tagged With: ,

Post: How to find MySQL queries worth optimizing ?

September 11, 2012 By 6 Comments

…Rows_examined=0 same as Rows_sent meaning this query is optimized quite well. Note you may be thinking in this case there is no database…A) – look at number of rows examined divided by number of tables in join (B) – if B is less or equals to A your query…

Filed Under: Insight for DBAs, MySQL

Post: High-Performance Click Analysis with MySQL

December 22, 2008 By 13 Comments

…to think outside the box, even to think of things that seem “less advanced” than using a database…to find a…a custom table, which is really constructed behind the scenes from the name-value tables in a complex query with…

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Post: How to recover deleted rows from an InnoDB Tablespace

February 20, 2012 By 4 Comments

…to explain three of them: A) INNODB_SYS_INDEXES Percona Server has some extra tables in INFORMATION_SCHEMA that can help us to find…rows With the data in our hands the last step is to import it in our database…

Filed Under: Insight for DBAs, MySQL

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

March 4, 2013 By 7 Comments

…in a later version. Now that we’ve sorted this out, let’s drop and rebuild our FT index on the InnoDB table…with out it. So, for example, if we change the above query to be “+james +peterson arizona” then we might expect to…

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

Post: Innodb row size limitation

April 7, 2011 By 12 Comments

…a given row on a single database page. Innodb has a limit for the maximum row size, which is slightly less than half a database…a BLOB instead of a TEXT column for storage. You can find more information about this functions here. Split the table in a…

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

Post: Analyzing Slow Query Table in MySQL 5.6

February 18, 2013 By 1 Comment

…Queries with Percona Toolkit.  This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database…

Filed Under: Events and Announcements, Insight for DBAs, Live Virtual Training, MySQL, Percona Toolkit, Training Tagged With: , , , , , , ,

Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

…queries to find an anomaly.  I am going to focus on the first query, which uses only one join. Since it is practical for a query with…

Filed Under: MySQL Tagged With: , , , , ,

Post: Eventual Consistency in MySQL

November 18, 2011 By 8 Comments

…rows in every parent-child relationship in your database.  That is, do an exclusion join from child table to its referenced parent table, and if no matching parent row…A,B. Generating SQL with SQL Now that we know the information in KEY_COLUMN_USAGE, we can write a query to…

Filed Under: Insight for DBAs, MySQL
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