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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.
Async is this, and yeah it's a bit clunky due to how you have to pass data inline or come up with your own exchange method (writing and loading sexps to & from files is viable, as are readable datastructures).
esxml is a code-generation library for Elisp, but the part that I use more often is in esxml-query.
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