22 Oct 2024 · GA4 · medium severity · fix verified 9 Sept 2026
BigQuery export adds session-scoped traffic-source fields
'The BigQuery export now includes additional session scoped traffic-source fields, including the cross channel and all other integration specific contexts.'
Source: What's new archive — Oct 22, 2024.
What it breaks
Queries that derived session source from the first event of a session disagree with the new fields; two definitions of 'session source' in one warehouse.
Who it hits: BigQuery users who built session attribution by hand.
The fix
Switch session-level attribution to the session_traffic_source_last_click record (the SQL does).
fix artifact · #A-004
GA4 BigQuery: sessions with last-click source and key events
One query over the events_* export: sessions per day, the session's last-click source from the record Google added in July 2024, and key events per session.
- verified_on
- 2026-09-09
- next re-check
- 2026-12-01
- status
- current
Sources linked on every entry · artifacts stamped and re-verified · ← all changes