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Storing UUID and Generated Columns

 | May 3, 2017 |  Posted In: Benchmarks, Insight for DBAs, MySQL

Storing UUID

A lot of things have been said about UUID, and storing UUID in an optimized way. Now that we have generated columns, we can store the decomposed information inside the UUID and merge it again with generated columns. This blog post demonstrates this process. First, I used a simple table with one char field that I called […]

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Replication Triggers a Performance Schema Issue on Percona XtraDB Cluster

 | October 21, 2016 |  Posted In: MySQL, Percona XtraDB Cluster

wsrep-stages

In this blog post, we’ll look at how replication triggers a Performance Schema issue on Percona XtraDB Cluster. During an upgrade to Percona XtraDB Cluster 5.6, I faced an issue that I wanted to share. In this environment, we set up three Percona XtraDB Cluster nodes (mostly configured as default), copied from a production server. We […]

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Speed up GROUP BY queries with subselects in MySQL

 | June 15, 2015 |  Posted In: 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 […]

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