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If you have a lot (=thousands) of small (less than 100 kB) items to store (experimental sentences, tweets, audio fragments, individual calculations, etc), it might be tempting to store them as individual files so the file system more or less reflects your data structure. This has the important downside, however, that the file system will become incredibly slow: a simple command like
ls is no longer instant, loading your data with a script might take ages, and most importantly: it will be practically impossible to move around your files, for example if they need to be moved to another disk for maintenance reasons.
There are multiple solutions