Deleting your places.sqlite file is the easiest, but the worst way of defragmenting it. The easiest (if you're using btrfs) is to run: `btrfs filesystem defrag

Deleting your places.sqlite file is the easiest, but the worst way of defragmenting it. The easiest (if you're using btrfs) is to run: `btrfs filesystem defragment ~/.mozilla/firefox/*/places.sqlite` or use ioctl(fd, BTRFS_IOC_DEFRAG, NULL). As far as I know, this can only be done as root. I'm not sure if other filesystems have similar defrag hooks. So the correct approach is to make this facility accessible from unprivileged userspace.