#9 - Breaking change: item-scoped custom parameters added to GA4 export schema
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:
- How to set up the Google Ads data transfer to BigQuery
- How to fix the major GA4 BigQuery export misattribution (part 2: join 'gclid' parameter with Google Ads data transfer and get your campaign data right)
- GA4 BigQuery export schema change log (or how to generate your own)
- Traffic source and user acquisition dimensions & metrics (GA4)
- How to create a GA4 user acquisition report in BigQuery
- How to create a session based GA4 traffic acquisition report in BigQuery
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 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
- BigFunctions: open-source functions to expand BigQuery capabilities
- Incremental Refresh Strategies for Dataform – GA4
- Dataform with GA4: The Unsung Hero of Marketing Analytics
- How does Dataform work? A primer on the ref function
That's it for now. Thanks for reading and happy querying!