DAU report timezone mismatch
Review this SQL that powers a 'daily active users' report. created_at is a UTC timestamptz; the business reports in America/Los_Angeles.
What a strong answer looks like
Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix, specific and kind.
0:00 of about 18 min
Mark a line and say what kind of problem it is.0 findings
1SELECT
2 date_trunc('day', created_at) AS day,
3 count(DISTINCT user_id) AS dau
4FROM events
5WHERE created_at >= now() - interval '30 days'
6GROUP BY date_trunc('day', created_at)
7ORDER BY day;
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