DD-TRF-003
Complex Joins, Exceptions and Transformation Logic
Decide which customer tier a sale belonged to on the day it happened, which rows break the exception rules, and what survives duplicate resolution.
- Data Transformation
- L3 · PARQUET
- ~514,953 rows
- 12 tables
- 50 questions
Get the data
v1.0 · 6 filesFiles are for members. A free account takes a minute, and you come straight back here.
- Question Book PDF DD-TRF-003_Question_Book.pdf
- Dataset Documentation / Data Dictionary XLSX DD-TRF-003_Data_Dictionary.xlsx
- Business Introduction PDF DD-TRF-003_Business_Introduction.pdf
- Relationship Diagram PDF DD-TRF-003_Relationship_Model.pdf
- Raw fact data DD-TRF-003_FactTransformationEvents.parquet
- Dimension / supporting data DD-TRF-003_Dimensions.zip
Questions
Open one to discuss it- Q001 Easy Rows in the export file
- Q002 Easy Exact duplicate rows
- Q003 Easy Conflicting duplicate IDs
- Q004 Easy Blank customer codes
- Q005 Easy Amounts stored as text
- Q006 Easy Dates not in ISO format
- Q007 Easy Codes with stray case or spaces
- Q008 Easy Unknown product codes
- Q009 Easy Return lines
- Q010 Easy Valid rows after cleaning
- Q011 Easy Reconciled total amount
- Q012 Easy Distinct customers after standardising codes
- Q013 Medium Clean amount by month
- Q014 Medium Valid rows by month
- Q015 Medium Distinct customers by month
- Q016 Medium Exact duplicates by month
- Q017 Medium Conflicting duplicates by month
- Q018 Medium Blank customer codes by month
- Q019 Medium Text amounts by month
- Q020 Medium Non-ISO dates by month
- Q021 Medium Stray-case codes by month
- Q022 Medium Unknown products by month
- Q023 Medium Return lines by month
- Q024 Medium Value of returns by month
- Q025 Medium Year-on-year change in clean amount
- Q026 Medium Clean amount by category
- Q027 Medium Clean amount by region
- Q028 Medium Rows per batch file
- Q029 Medium Drifted columns per batch file
- Q030 Medium Batch rows absent from the export
- Q031 Hard Regions driving the year-on-year change
- Q032 Hard Category standardisation bridge
- Q033 Hard Reconcile batch Batch_2025_07 to the export
- Q034 Hard Reconcile batch Batch_2025_08 to the export
- Q035 Hard Reconcile batch Batch_2025_09 to the export
- Q036 Hard Reconcile batch Batch_2025_10 to the export
- Q037 Hard Reconcile batch Batch_2025_11 to the export
- Q038 Hard Reconcile batch Batch_2025_12 to the export
- Q039 Hard Sales by customer tier as at transaction date
- Q040 Hard Rows breaking the exception rules
- Q041 Hard Monthly rates against a flat rate
- Q042 Hard Top ten products before and after cleaning
- Q043 Very Hard Checksum of the final table
- Q044 Very Hard Conflicting duplicates: amount at stake
- Q045 Very Hard Survivorship by latest load
- Q046 Very Hard Customers collapsed by alias mapping
- Q047 Very Hard Sales re-tiered by the SCD change
- Q048 Very Hard Schema drift in batch Batch_2025_09
- Q049 Very Hard Schema drift in batch Batch_2025_12
- Q050 Very Hard Incremental load across all batches
General discussion
Anything about this dataset that is not one question — loading the files, which tool, how you set it up.
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