... Also known as a very simple case of a “column-oriented database”, of which are several at various scales from Metakit[1] to Clickhouse[2]. It’s a neat way to have columns which are sparsely populated, required to accommodate large blobs, numerous but usually not accessed all at once, or frequently added and deleted.

Nothing’s perfect, of course: you can’t stream records in such a format, so no convenient Unix-style tooling.

[1]: http://www.equi4.com/metakit.html [2]: https://yandex.com/dev/clickhouse/

Higher performance, much smaller compressed and uncompressed, accepted by a wide range of tools, e.g. Pandas, and often more convenient to parse from statically typed languages.