Install an old MariaDB version on Ubuntu

Do you need to install an old version of MariaDB on Ubuntu? Maybe you need to do some testing. Here’s how. Visit https://mariadb.com/downloads/ and choose your package and OS. You’ll download a tar fie. Extract the tar file with tar xf mariadb*.tar. Change your working directory to the extracted directory. cd mariadb*debs Set up your … Read more

Reindexing tables with bad dates

Sometimes, upon adding indexes to MariaDb or MySQL tables with columns with zero-default dates you’ll get an error message like this: This happens because your server’s default sql_mode includes the NO_ZERO_DATE value. It is prevalent when working on WordPress indexes using phpmyadmin or some other MySQL client program. To prevent it, change the sql_mode before … Read more

Real users slow applications down

Anybody who’s worked with databases knows this: as they grow they can slow down. It’s the curse of the customer base. Successful applications gather users and other transactional data. In this article I’m using MySQL database queries based on WordPress’s database design. Still, the ideas in this article apply to every application built on any … Read more

Capturing and examining queries

This entry is part 2 of 2 in the series WordPress MySQL performance monitor

It’s straightforward to get WordPress to capture the MySQL queries it uses to generate each page view. We can then analyze the captured queries. Capturing WordPress offers a way to capture a list of the database queries it uses in each page view. It’s simple: define the global SAVEQUERIES symbol. You can define it permanently … Read more

Analyzing WordPress database operations

This entry is part 1 of 2 in the series WordPress MySQL performance monitor

People are using the Index WP MySQL For Speed WordPress plugin! That’s great. But it shoots into the dark: nobody can tell how much improvement they’ve seen except subjectively. That’s not good. It’s hard to improve something unless we can actually measure it. Two things can make a troublesome query. If it runs just once … Read more

Legacy MySQL VMs

Installing old versions of MySQL is a giant pain. An AskUbuntu contributor gave a workable procedure. Need to run MySQL 5.5? Download this VM. Running MySQL 5.7 is easier. Install Ubuntu 18.04, then do sudo apt install mysql-server-5.7 .

Porting from CEFSharp to WebView2

I have a Windows Presentation Foundation app using CEFSharp as a browser control. I’m porting it to use the new WebView2 control from Microsoft. That’s a workable idea now because it embeds a new Edge object in the WPF app. So, there’s no need to download the whole Chromium Embedded Framework mischegoss which saves download … Read more