In the fifteenth year of my software developer career, I encountered a remarkable bug that would “entertain” me for weeks.

“Garbage in, garbage out”?

It started off rather innocuously: At a recently-installed customer site, I noticed that a few XML files sent from the editorial system weren’t imported correctly into our DAM system. The files were imported, but parts of the data looked bad.

My first assumption was that the editorial system had generated faulty files – “garbage in, garbage out.” But they seemed no different from successfully-imported files, and when I reimported the files that originally failed, the problem was gone.

I had no idea where to look and decided to live with the problem for a while. Each day, I checked for failed imports and manually triggered a reimport. But sooner or later I would have to find and fix the cause.

Today, I needed to copy a few tables from a PostgreSQL database into a MySQL database. I wanted to use XML files to exchange the data so I could inspect and validate it easily.

I expected this to be a lot of work (including XSLT magic), but it was surprisingly easy: It turns out that PostgreSQL’s default XML output format is supported by MySQL out of the box!