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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.
There is this free book by Allen B. Downey, Think DSP. I haven't read it enough to comment on it. I have, however, read other books by the same author and I do like his writing, explanation and approach, in general.
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