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Incorrect customer join

Orders were remapped to customer_uuid. A finance report still joins customers.email and fans out on collisions. Restore the intended order-to-customer map using the mapping table.

FieldDetail
CreatorPipelineArena · expert
Version2.0.0
Time30 min
Credits2
Completion0% · 0.0 rating
Hidden tests4

Objective

The report has one row per order, joined on the surrogate key, with unmatched orders listed.

#Success condition
1No fan-out: report row count equals distinct order_id
2Join uses customer_uuid / mapping table, not email
3Orphan orders appear in unmatched_orders
4Checksum of (order_id, customer_uuid) matches the hidden map
#Visible instruction
1Compare report row counts to orders.
2Use customer_key_map from the migration.
3Leave unmatched_orders for operations — do not drop them.
Hidden tests score the final tables or files, not the exact syntax you used. Test implementation is never shown to participants.

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