Comment by tristor

I really love Calibre and I've been using it for more than a decade. But one thing I'd really hope to see that hasn't happened yet is support for alternative database backends. Unfortunately if you have enough ebooks, it becomes impossible for the Calibre software to scale to handling them and a big piece of this is internal limits placed on the size of its database file. I have such a large quantity of ebooks on my media server (terabytes of ebooks) and have never been able to successfully add all of them to Calibre to be managed as a single library.

I'm glad to see that development continues, this has been an utterly essential tool as I've switched between different ebook readers over the years.