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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
No idea if it supports what you need but toybox has an implementation of tar.
(WIP) Non-GPL implementation - https://github.com/michaelforney/pax
bsdtar is built on top of libarchive which is mostly under a BSD-2-clause.
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