I have a picture gallery website I put together with various plugins and dirty file editing hacks. For example I had to make sure jetpack infinite scroll plays nice with theme's masonry and lazy loading of images which are read from a custom field! etc..
I grow tired of spending time on making sure plugins and hacks play to nice with each other, and I really want to be able to update my wordpress and plugins etc. So I created my own theme from scratch. I'm pretty sure my theme is ready to be deployed live. But there is one little problem.
I was using "Nelio External Featured Image" plugin, so all of my images are stored with its own custom field "_nelioefi_url". I want to change it to "external_thumbnail". For 20k posts. Before cloning the database offline and using mysql update commands, I wanted to ask if someone knows an easier way.