Originally Posted by sirbruce
Calibre seems to do a linear check for duplicates for every file, and the time it takes to do this seems to grow exponentially. If there were a way to turn off check for duplicates, the import might go faster, but otherwise, no there's no easy way to add new books to a large database.
Guess i'll keep trying with smaller batches... but boy its frustrating to come back after 6 hours and see that calibre has crashed or that it found some duplicates, you click on "ok" and it goes into none responsive mode to never come back...
I thin you are right, the check for duplicates is causing some problems, turning it off might be a good solution. In any case it really doesn t matter as at the end it asks you if you want to include the duplicates... i always say yes as i deal with various format, so its kind of redundant.