How to select a right database for IoT gateway?

Question

Assume I build a IoT gateway (Linux OS) for collecting data from sensors. Data is store on database, and can be viewed via a web server implement on this gateway. Storage is not much, about 2GB. Which database is a good choice for this situation? RDBM or NoSQL or Time series? In my positon, I think no need both NoSQL and Time series, just going on with traditional RDBM. Is it good? Please give me some advices.

Add more info:

• Each sensor will send temperature, voltage, etc.
• Data visualization for each sensor in one hour, one day or one month. (I think it is good for the max period is in one month)
• And track all every single value. Example: gateway want to read data from a sensor in a moment, but it could not get for some reasons (sensor is die, disconnect to network, etc). So, this moment will be track and set it's value to null (or a value point out that could not get data from sensor in that moment). When you view data visualization, you will know in that time, it was a problem with sensor or network.

Answer 1

It doesn't sound like you will have much data so I would go with whatever you are most comfortable. If you are proficient with SQL, I would use a SQL database such as MySQL or Postgres.

Once you get into higher volume, hundreds to thousands of inserts per second, then I would look into a time series database. They can handle high ingestion and provide easier query methods for wrangling with the data.

I wrote a blog post about how to query a regular database vs a time series database (Hyprcubd). https://blog.hyprcubd.com/time-series-graph/

Answer 2

If I am understanding correctly you are saying Time-series database like this one right?

Then you should go with the Time series database as you said:

Data visualization for each sensor in one hour, one day or one month. (I think it is good for the max period is in one month)

And also:

Each sensor will send temperature, voltage, etc.

So the best option is to view the data on the graph with the view of every 5-10min, an hour, a day or a month. As shown in the above example image.

If as you said:

And track all every single value. Example: gateway want to read data from a sensor in a moment, but it could not get for some reasons (sensor dies, disconnect to network, etc). So, this moment will be track and set it's value to null (or a value point out that could not get data from the sensor at that moment). When you view data visualization, you will know at that time, it was a problem with sensor or network.

when the sensor dies the plot on the graph will be "null=0" showed with the time and date reference.