PROFILE BEFORE PATTERNS
Source filename/version and unchanged original location:
Unit/key and scope/cutoff:
Check | observed result/count | implication | action if failed:
- Record count and unique/nonblank keys.
- Parse UTC timestamps; check event order and cutoff.
- Assign creation cohorts; count outside-scope rows.
- Check response/resolution maturity and valid elapsed units.
- Allowed categories; observed rating range.
- Missingness by field, cohort AND channel.
- Reconcile retained/excluded/source counts; distinguish documented blanks from defects.
Conclude what can proceed, what remains unavailable and which claim cannot be supported.