Anybody else noticed that Percona appears to not be a US entity any more?
I observed it today.
$ sudo /usr/bin/innobackupex ... InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy and Percona Ireland Ltd 2009-2012. All Rights Reserved. This software is published under the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.
In previous versions this did say Percona Inc, 2009-2012.
The footer of the Documentation also states © Copyright Percona Ireland Ltd. 2009-2013.
MySQL’s built-in AVG() computes the arithmetic mean — the sum divided by the count. That is the right default for many questions, but it is not always the right measure of central tendency.
MySQL offers three different approaches to extending the SQL capabilities with the default product you download and install. These are: User Defined Function (UDF) MySQL Manual MySQL Plugin MySQL Manual MySQL Component MySQL Manual For the purposes of this post I will be using the current LTS version MySQL 8.
The one-sample Z-test determines whether a sample mean differs significantly from a known population mean when the population standard deviation is also known. It is the appropriate test when the population parameters are established — quality control benchmarks, national averages, long-run process measurements — and you want to evaluate whether a new sample is consistent with them.
