Explore Anomalies

Outliers: Unusually high or low values. Example: Transaction amount of $10,000 in a dataset where typical values are between $10–$200.

Negative or Invalid Values: Negative entries where they don’t make sense. Example: −50 in a “Quantity Sold” column.

Column order: The column “Product Name” appears at the end but is typically expected directly after “Product ID” for logical organization.

Suggested fix: Reorder columns to Product ID → Product Name → Sales (USD) to improve readability and schema consistency.

Logical Disperancy

• Col 1 (Location 101 – Sydney): In the Southern Hemisphere, July is winter; a temperature of −20°C is extremely unlikely.
• Col 2 (Location 102 – Toronto): In the Northern Hemisphere, December is winter; 40°C is implausible.

Anomaly

• Col 1 (C001 – “Atlantis”): Refers to a mythical city; population value is factually invalid.
• Col 2 (C002): Population is negative (-500), which is impossible.

Anomaly

• Employee ID E001: Check-Out Time (09:00 AM) occurs before the Check-In Time (05:00 PM) on the same date, which is temporally inconsistent.
• Employee ID E002: The shift spans midnight (10:00 PM → 02:00 AM) but Work Date remains the same; the end time should be recorded on the next day (2024-03-02) or marked as an overnight shift.

Anomaly

• Profit formula: Profit = Revenue − Expense.
• Business ID 302: 200,000 − 180,000 = 20,000; declared profit is 5,000, suggesting possible underreporting.

Anomalies

1. Phone Number uses inconsistent formats:
   • Customer ID 101 uses parentheses and a dash — (123) 456-7890.
   • Customer ID 103 is unformatted — 1234567890.
   • Customer ID 104 uses international spacing — +1 123 456 7890.
2. Name duplication: John Doe appears for both Customer ID 101 and 104, suggesting a possible duplicate entry.

Anomaly

• Sensitive data in clear text: The table exposes full Credit Card Numbers (PAN). Storing or displaying PAN without masking/encryption violates security best practices and risks data exposure.
• Mitigation: Mask PANs (e.g., **** **** **** 9012), tokenize or encrypt at rest, and restrict access to authorized roles only.

Anomalies

• Partial dependencies: Employee Name depends on Employee ID, while Manager Name and Manager Contact depend on Project ID (part of a composite key).
• 2nd Normal Form (2NF) violation: Non-key attributes (Manager Name, Manager Contact) depend on only part of the primary key (Project ID), not the full composite (Employee ID, Project ID).
• Suggested design: Move manager details to a separate Projects/Managers table keyed by Project ID; keep employee-specific data in the current table and link via Employee ID and Project ID.