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GA4 | newsletter

#9 - Breaking change: item-scoped custom parameters added to GA4 export schema

— Johan van de Werken

Hi there,

A warm welcome to the 189 new subscribers who joined since the last newsletter! It's time for your monthly update on GA4 and BigQuery.

New / updated articles on GA4BigQuery

Since the last newsletter we have added and updated these articles:

Item-scoped parameters added to GA4 export schema

Let's start with the good news: custom item-scoped parameters (custom dimensions for your ecommerce products) are finally available in the GA4 BigQuery export. Here is how to unnest these fields and use them in your queries and reports.

The GA4 BigQuery export schema can be considered a 'work in progress'. New fields are added periodically, which can cause your queries and pipelines to break because the new fields are not added for historical data. BigQuery will alert you that it doesn't recognize these fields when querying a wider date range.

GA4 export schema change log

This is exactly what happened, causing a lot of trouble amongst data teams world wide. In contrast with other vendors, Google didn't bother to send a notification upfront that a breaking change was to be expected.

Also, Google is not really transparent about schema changes. There is no official schema change log. This inspired some Measure Slack members (join us!) to document the most important changes and - while at it - develop a way to generate your own GA4 export schema change log.

BigQuery update

BigQuery native integration in Looker Studio enables monitoring features for Looker Studio queries, improves query performance, and supports many BigQuery features. This feature is in preview.

Relevant blog posts and resources from the community

That's it for now. Thanks for reading and happy querying!

Best regards,