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Firstly and concretely, I'd like to demonstrate two industrial scenarios as well as the SQL and the query result format. If it makes sense, we could add SQL formats to the IoTDB as the first step of the IoTDB index mechanism.

Case 1: Erythromycin Fermentation

The figure above shows the IoTDB schema for the Erythromycin Fermentation. Some irrelevant information has been omitted. The pharmaceutical factory has many fermentors (Ferm 01, Ferm 02, etc.), each of which produces erythromycin batch by batch.

For each batch (e.g., batch-20191017), the factory will monitor some measurements in the fermentation process, like glucose feeding rate (Glu), carbon dioxide exit rate (CER), and pH value. Researchers have found that the glucose feeding rate is critical to the final erythromycin output. Therefore, analysts want to build a similarity index (e.g. RTree+PAA index) for on Glu sequences for all fermenters and all batches. After building the index, the analyst inputs a Glu sequence, finds batches with similar Glu curves, and makes further analysis.

Index Creation

The SQL format of index creation statement is as follows:

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 CREATE INDEX ON root.Ery.*.Glu 
 WITH INDEX=RTreePAA, PAA_dim=8

Index Query

The analyst hopes to find the two Glu sequences closest to the given query Glu sequence in all fermenters and batches. The index query statement is as follows:

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Note that after a fermentation batch is completed, the series has been fixed, and will not be appended or renewed. Because of the regular productivity, we can suppose that all series among batches and fermenters have similar lengths.

Index Drop

The index drop statement is as follow:

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 DRRP INDEX RTreePAA ON root.Ery.*.Glu 

Case 2: Extreme Operating Gust

The above figure shows the IoTDB schema of a wind turbine manufacturer. The manufacturer has many wind turbines (AZQ01, AZQ02, etc.), each of which continuously monitors the state of the turbine itself and the surrounding environment, such as wind speed, wind direction, generator power, etc. The analyst hopes to build an index (e.g. ELB index) for the speed series of AZQ02 (root.Wind.AZQ02.Speed). After building the index, the analyst inputs a EOG pattern (Extreme Operating Gust), finds all results in speed series for further process control, fault diagnosis and predictive maintenance.

Index Creation

The index creation statement is as follows, similar to the above case:

 CREATE INDEX ON root.Wind.AZQ02.Speed
 WITH INDEX=ELBIndex, Block_Size=5

Index Query

The query condition and the result format are the main differences from the above scenario.

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Since the monitoring process is continuous, the new-coming data will be inserted into the index continuously.

Index Drop

Similar to the above case.