MS Fabric Notebook: Error when using dataframe.to_json() with Fabric Lakehouse storage

Hi trutz ,
Thanks for using Microsoft Fabric Community.

The error message "4263942" is a generic error that can occur in a variety of contexts. It typically indicates a problem with a large dataset. For example, it could occur if the dataset is too large to be processed by the computer, or if the dataset is corrupted.

A DataFrame of size 4263942 is approximately 4.1 gigabytes. This is a relatively large DataFrame, and it is possible that your computer does not have enough memory to convert it to a JSON string. The error message "4263942" indicates that the size of the JSON data is too large to be written to Fabric Lakehouse storage. The maximum size of a JSON file that can be written to Fabric Lakehouse storage is 4 MB.

The specific size limit for a DataFrame depends on the amount of available memory on the computer and the complexity of the Pandas operations being performed. However, it is generally recommended to avoid using DataFrames that are larger than a few gigabytes.

There are a few things you can do to try to fix the error:

1) Reduce the size of the DataFrame. You can do this by selecting a subset of the rows or columns in the DataFrame.
2) Use a streaming JSON library. Streaming JSON libraries can convert DataFrames to JSON more efficiently than the built-in JSON library in Python.
3) Use a distributed computing framework. This allows you to distribute the workload across multiple computers.

Hope this helps. If you have any further questions or requests, please do ask.