SQLite also performs well when there is a large number of "files". A simulation I wrote used a large number of files (10k+). Eventually I had to transition away

SQLite also performs well when there is a large number of "files". A simulation I wrote used a large number of files (10k+). Eventually I had to transition away from using the file system as a key-value store because open, reads, writes, and directory listings were slow when you have that many files in a single directory and that many open file descriptors.