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A case for MariaDB’s Hash Joins

 | May 31, 2012 |  Posted In: Benchmarks, Insight for DBAs, MySQL

MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I will show the results of executing benchmarks […]

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Joining on range? Wrong!

 | May 17, 2010 |  Posted In: Insight for Developers, MySQL

The problem I am going to describe is likely to be around since the very beginning of MySQL, however unless you carefully analyse and profile your queries, it might easily go unnoticed. I used it as one of the examples in our talk given at phpDay.it conference last week to demonstrate some pitfalls one may […]

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JOIN Performance & Charsets

 | October 21, 2008 | 

We have written before about the importance of using numeric types as keys, but maybe you’ve inherited a schema that you can’t change or have chosen string types as keys for a specific reason. Either way, the character sets used on joined columns can have a significant impact on the performance of your queries. Take […]

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Join performance of MyISAM and Innodb

 | May 29, 2006 |  Posted In: Benchmarks

We had discussion today which involved benchmarks of Join speed for MyISAM and Innodb storage engines for CPU bound workload, this is when data size is small enough to fit in memory and so buffer pool. I tested very simple table, having with about 20.000 rows in it on 32bit Linux. The columns “id” “i” […]

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