November 12 2024 Mariadb permissions, databases, visually impaired users, Stellarium

Mike had had problems in connecting MODX with mariadb. John wondered if this was a permissions problem as mariadb changed the way it handles permissions as set out during the meeting on 13 April 2021. Now there are five ways of handling permissions:

1. mysql_native_password which uses SHA-1
2. unix_socket which relies on a Linux user having logged in using their user password
3. named_pipe which relies on a Windows user having logged in using their user password
4. ed25519 which uses the same authentication as OpenSSH
5. gssapi which is primarily intended for use with Kerberos on both Linux and Windows
6. pam which relies on PAM authentication being installed.

It seems likely that Mike will need to use one of the last three to connect to MODX. None of these are installed by MODX; you have to set them up yourself first and then use them to connect to MODX.

Steve commented that, apart from sqlite, he had never used databases. John said that he had used dBASE II on CP/M after buying it while on holiday in Germany because it was much cheaper than in England and because he was about to start a management course. It was very similar to SQL because it had been developed at NASA’s Jet Propulsion Lab around the time that SQL was being developed. So there were only a couple things where dBASE II and SQL did things the opposite way and it had been fairly easy to transfer all his dBASE II files to mysql when he started using Linux.

This prompted Steve to mention that he had used CP/M on an RML380Z which was also the first computer which John had used, initially with WordStar, whose scripting language allowed the automation of tasks, after which he had used an Apple II with CP/M and then an Amstrad CPC 6128. The great thing about WordStar, dBASE II and SuperCalc was that they could share data; so dBASE II data files could be used for WordStar mailmerge.

Steve then queried the point of the mysql permissions, as he assumed that anyone with root access could also access mysql data files. John couldn’t answer that; just say that you always had to have a separate password for mysql and so he had assumed that they would not be accessible to anyone without permission. Bernie pointed out that most databases run on secure servers and so it would not be possible to access them without access to the server.

John said that the key innovation brought by mysql was permissions by column so that people could use the same database but not all have access to all the columns, something not available in Approach or Access. Though MySQL offered support contracts, they also made the program available free and reckoned that 1,000 were using mysql free for every one paying for support; however these 1,000 users provided invaluable feedback which enabled them to improve mysql much more quickly than if they had relied on their paying customers.

mysql was acquired by Sun but concerns about the way Sun was managing mysql led Monty Widenius to fork it as mariadb (My and Maria are the names of Monty’s daughters) much as OpenOffice had been forked to create LibreOffice after OpenOffice had been acquired by Oracle.

John then gave a presentation on creating websites which are equally accessible to visually impaired and to sighted users [for which there is a more detailed PDF], followed by demonstrations of how the same website can appear, using lynx heatholdboys.org.uk from the command line, as a continuous sequence of article, menu and links to a screenreader user and, using https://heatholdboys.org.uk/ in a browser, as an article between a menu on the left and links to other material on the right to a sighted user.

Bernie concluded the evening with a brief introduction to Stellarium, highlighting the meteor shower due on Monday, 18 November 2024.

Past Meetings