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DA0-002 · Question #8

A data analyst pulls a table similar to the following one: Which of the following best explains the data issue with TypeID?

The correct answer is A. Redundancy. Assuming the TypeID column shows multiple entries for the same conceptual type or inconsistent mapping, the best description of the data issue is redundancy. Redundancy occurs when the same information is stored multiple times or can be derived from other data within a schema.

Data Concepts and Environments

Question

A data analyst pulls a table similar to the following one:

Which of the following best explains the data issue with TypeID?

Options

  • ARedundancy
  • BOutlier
  • CMissing data
  • DDuplication

How the community answered

(43 responses)
  • A
    72% (31)
  • B
    16% (7)
  • C
    2% (1)
  • D
    9% (4)

Why each option

Assuming the TypeID column shows multiple entries for the same conceptual type or inconsistent mapping, the best description of the data issue is redundancy. Redundancy occurs when the same information is stored multiple times or can be derived from other data within a schema.

ARedundancyCorrect

Redundancy in data refers to the presence of duplicate data in multiple places or when information can be inferred from other stored data, which often indicates a database design flaw. If TypeID should uniquely identify a Type, but shows multiple entries for the same Type or inconsistent TypeID-to-Type mappings, this indicates redundant information.

BOutlier

An outlier is a data point significantly different from other observations, which is not the primary issue described by an inconsistent or repeated TypeID mapping.

CMissing data

Missing data implies an absence of values, not an issue of repeated or inconsistently mapped existing values in TypeID.

DDuplication

While duplication can be a form of redundancy, 'redundancy' is a broader term encompassing semantic repetition or information that is unnecessarily stored, often due to a poor data model, which better describes inconsistent TypeID mappings.

Concept tested: Data redundancy, data integrity

Source: https://en.wikipedia.org/wiki/Data_redundancy

Topics

#Data Quality#Data Redundancy#Database Normalization#Data Issues

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