Author: George Georgovassilis

Ubuntu 20.04 not resolving local network hostnames

An Ubuntu 20.04 laptop installation started not being able to resolve the names of hosts in the same local network. Although the host names were registered with the router, the laptop wouldn't be able to resolve those host names. Surprisingly, neither netbios resolution worked (although nbtscan would find those hosts). The solution is to bypass … Continue reading Ubuntu 20.04 not resolving local network hostnames →

Single push-pull amplifier with cross over compensation

There is a Mandarin translation of this post. This is just going to be a quick one. Double push-pull amplifier with cross over compensation explained a high-power amplifier circuit which creates a balance point and corrects for cross over. A much simpler version of the circuit depends on two equal voltage sources creating that 0V … Continue reading Single push-pull amplifier with cross over compensation →

Mysql: the definition of table prevents operation … on table

This is a tricky one affecting MySql table updates which have views. Documentation about this error actually explains the cause, but doesn't connect the dots. I have a view V on table T and want to delete some rows from T. That works fine as long as the DELETE statement doesn't involve the view, so … Continue reading Mysql: the definition of table prevents operation … on table →