BigQuery to Data Studio discrepancy for event 'first_open'

0
votes

We've exported data from Firebase Analytics (events) to BigQuery for use in Data Studio.

When we try to match data with BigQuery/DataStudio with the Firebase console, literally every event total count matches, except for the first_open event.

Is there any explanation for this?

1
firebasegoogle-bigqueryfirebase-analyticsgoogle-data-studio
Please contact Firebase support if you have questions about the data you see in the Firebase console. support.google.com/firebase/contact/support – Doug Stevenson

1 Answers

1
votes

This was the answer of Firebase Support:

Discrepancies after linking Analytics data with BigQuery are to be expected. You can try using the following best practices to get better results:

  1. Instead of using user_id, make use of user_pseudo_id (which is the user identifier for Analytics reports).
  2. Use the table for a specific day instead of using a date comparison on the event timestamp in the WHERE clause. The event timestamp is based on client device time, which is often skewed.
  3. Never compare events like session_start or user_engagement that are triggered quite often.
  4. Always get a report past 3 days so that the data exported from GA4F to BigQuery gets normalized. Data is only exported to BigQuery once per day. And so, queries which include the most recent three days will show different results between Analytics and BigQuery.

Also, Google Analytics for Firebase is using HyperLogLog (HLL) proximation algorithm to calculate the user count. This provides more flexibility when filtering user metrics by user properties and audiences, but could cause the discrepancy in the event count.