If you've ever tried pulling a monthly GA4 report in BigQuery, you've probably run into this lovely setup: events_YYYYMMDD.
That’s right - one table per day. Want a week’s worth of data? Guess how many tables you’re dealing with.
Enter the hero of the day: _TABLE_SUFFIX.
It lets you write a single query across multiple tables—no pain, no copy-paste, no SELECT FROM events_20250701 UNION ALL....
How does it work?
Just write:
FROM `your_project.your_dataset.events_*` WHERE _TABLE_SUFFIX BETWEEN '20250701' AND '20250707'.
BigQuery will go: “Got it, you want July 1 to July 7.” Smart, clean, almost magical.
Things to keep in mind:
• events_* is a wildcard. _TABLE_SUFFIX won’t work without it.
• _TABLE_SUFFIX isn’t an actual column in your data — it's a let's say pseudo-column. You can filter by it, but you can’t SELECT it directly (unless you cast it to a DATE or handle it carefully).
• The values are the suffixes of your tables- usually in YYYYMMDD format.
Use case example:
Want to count all purchases in a week? Just replicate screenshot logic. No UNION, no mess—just clean SQL and peace of mind.
Takeaway:
GA4 splits your data into tiny daily tables. Great for Google’s infrastructure.
For you? It means learning to use _TABLE_SUFFIX, so you don’t end up writing 31 UNION ALLs at the end of every month.
But once you master it, working in BigQuery gets a whole lot easier.
Want to get all my top Linkedin content? I regularly upload it to one Notion doc.
Go here to download it for FREE.
