Session Id with multiple session number for the same user

[abenramd]

Hello Everyone, 

I'm currently working on GA4 data stored in our BQ. While digging into it, I found that for a given day and user, there are multiple session numbers, which seems weird to me!

Indeed, I thought the unique key for a session is the concatenation of user_pseudo_id & ga_session_id, but in this case, it's not a valid approach.

Here's the example I'm referring to:

Note: I replaced the real user_pseudo_id and ga_session_id  with fictive data for confidentiality reasons.

Thank you! 

Anes