Synthetic CSV quality audit: missing, duplicate and invalid data by Greg HellermanSynthetic CSV quality audit: missing, duplicate and invalid data by Greg Hellerman
Synthetic CSV quality audit: missing, duplicate and invalid data
Fictional data, not client work. AI-assisted preparation with checked arithmetic. This demonstrates a review method, not customer results or production throughput.
Agreed rules: exact text IDs must be present and unique; quantities must be integers. Negative quantities are flagged for owner review, not declared wrong. No values are changed.
Rows 2 and 3 repeat key 002 with different quantities. This is a key collision, not an exact duplicate. Row 4 lacks an ID. Row 5 has an invalid integer. Row 6 has a negative quantity requiring a business-rule decision.
Five distinct rows are flagged. Five numeric quantities total 27: 10 + 7 + 8 + 4 - 2. The invalid value is excluded and listed explicitly; 27 is a numeric subtotal, not a complete business total. Leading zeros are preserved.
The deliverable is a row-level issue register, column checks, a subtotal with exclusions, and questions for the data owner. No guessed repairs or silent source changes. Checks verified both totals and the exact flagged row identities 2, 3, 4, 5 and 6.
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Posted Sep 20, 2026
Fictional AI-assisted audit: six rows, five review flags, and a numeric subtotal that explicitly excludes an invalid value. No client work.