If the dataQuery is too large, not all data is captured

[jamtholee]

For example, Garmin Fenix 5 gives a data reading every 2 minutes: With a study that asks for HR every 3 days, it only captures 1.5 days' worth of data for some reason.

I don't think it's a limitation of JS (max size of array is 2^32 which we don't hit). Potentially it's the maximum amount of data the HealthKit API can return in one go?

[dariosalvi78]

The Data Query view cuts the data to the first 100 samples if I recall correctly, so don't rely on the view. Or, are you saying that this is what you observe on the received data?

[jamtholee]

What is observed on the received data - There's fairly big gaps on my data

[dariosalvi78]

I think there is a limitation on the HealthKit side. It's important to keep this behaviour under the radar then..