Interesting, adding tags to multiple books is slow. That is probably something that can be optimized. Opena ticket for it and I'll look into it.
As for import, I wouldn't recommend importing more than about a 1000 books a shot. That is because importing is a very messy process, calibre has to read metadata from book files and for some formats (particularly PDF) calibre relies on third party libraries to do the heavy lifting, not all of which are as stable/leak proof as I would like.
|