Understanding the time-series technologies

The IIoT process requires a continuously high data flow from the machines to the central system. This cannot be supported by a standard SQL database. For this reason, with IIoT, we prefer to use technologies inherited from big data, such as NoSQL databases. NoSQL databases are storage systems that can manage big data very efficiently by providing low support for aggregation functions and relationships among data. In the IIoT, the most common database is the historical database, which can store events, such as alerts or signals and measures, using a time-based method, where the timestamp is the key, or one of the keys, of the item. The most common historical database is the TSDB. A time series is a series of observations captured over a period of time, but in the IIoT, it has to support more information. A typical time-series-based item would look as follows:

Figure 7.4 – A time-series item example

The NAME...