Single collection for multiple keys

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Question :

I built a little setup with a raspberry pi and a temperature and humidity sensor. Every 5 minutes it reads sensor values and sends them both + a timestamp and a custom ID (there are multiple pis, each with its own ID) to a nodejs API which then stores them in a single mongodb collection. A GET request to this API then returns all objects from the collection with the id provided via GET.

Here is a json sample object of the data structure from my collection:

    "_id": "5c935a046b4fcc27f2a81cd8",
    "id": "livingroom",
    "time": "2019-03-21 10:31:48.601374",
    "temp": "22.0",
    "hum": "46.0"

Im pretty new to mongodb and databases in general but my programming experience tells me that just dumping everything into a single collection is not a good way to handle my data (propably, I really don’t know).

So my question is: Are there any big gotchas of me handling my data like this or am I fine for this projects scope? Do I need to expect big performance hits if this collection gets too big?

Answer :

The data you are generating from raspberry pi, temperature and humidity sensor is a time series data. MongoDB has documented some best practices and key tips for storing the time series data.

Time Series Data and MongoDB: Part 2 – Schema Design Best Practices

This explains the following schema patterns for time series data.

Scenario 1: One document per data point

Scenario 2: Time-based bucketing of one document per minute

Scenario 3: Size-based bucketing

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