Tag - David Ducos

Testing MySQL partitioning with pt-online-schema-change

There are cases where we need to implement MySQL partitioning, or at least test if it is an option to solve an issue. However, how are we able to test it when the table on our production environment has hundreds of millions of rows, several composite indexes and/or the size on disk is hundreds of gigabytes?
Testing […]

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Speed up MySQL Queries GROUP BY with subselects

Speed up queries on MySQL

We usually try to avoid subselects because sometimes they force the use of a temporary table and limits the use of indexes. But, when is good to use a subselect?
This example was tested over table a (1310723 rows), b, c and d ( 5 rows each) and with MySQL version 5.5 and 5.6.
Let’s suppose […]

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Importing big tables with large indexes with Myloader MySQL tool

Mydumper is known as the faster (much faster) mysqldump alternative. So, if you take a logical backup you will choose Mydumper instead of mysqldump. But what about the restore? Well, who needs to restore a logical backup? It takes ages! Even with Myloader. But this could change just a bit if we are able […]

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