DP-900 Describe core data concepts Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Structured (customer table), Semi-structured (JSON), Unstructured (JPEG)

  Why this is correct

  A relational customer table has a fixed schema, so every row shares the same defined columns and data types — that is structured data. JSON documents are self-describing: they contain key-value pairs that can vary from document to document, which classifies them as semi-structured. JPEG images store raw pixel and compression metadata without any queryable semantic fields, so they are unstructured. Therefore, this mapping accurately applies the three data categories to the three storage types.

• ✗

  Structured (customer table), Unstructured (JSON), Semi-structured (JPEG)

  Why it's wrong here

  The customer table is correctly identified as structured because relational engines enforce a fixed set of columns and data types for all rows. However, JSON is mislabeled as unstructured: it uses explicit key-value pairs and nested objects that carry their own schema, so it is semi-structured. JPEG data is compressed bitmap data without semantic tags or field names, so it is the opposite of semi-structured — it is unstructured. This answer fails on the last two classifications.

  When this WOULD be correct

  This option would be correct if the question defined 'structured' as any data with a fixed schema (including JSON with a strict schema), 'unstructured' as data without a schema (including JPEG), and 'semi-structured' as data with partial schema (e.g., JPEG with EXIF metadata).

• ✗

  Semi-structured (customer table), Structured (JSON), Unstructured (JPEG)

  Why it's wrong here

  The customer table is relational, meaning it enforces a rigid table-and-column design, so it cannot be semi-structured — the schema is fixed and uniform across rows. JSON, by contrast, uses tags and key-value pairs that allow fields to differ per record, which is the hallmark of semi-structured data, not structured data that sits in a rigid tabular form. The JPEG remains correctly labeled as unstructured because it is a binary file format with no inherent schema. This option mismatches the first two classifications.

  When this WOULD be correct

  If the question classified data types differently, e.g., a customer table with sparse or variable columns (semi-structured), JSON with a fixed schema (structured), and JPEG with metadata (semi-structured), then option C could be correct.

• ✗

  Unstructured (customer table), Structured (JSON), Semi-structured (JPEG)

  Why it's wrong here

  Calling the customer table unstructured ignores the fact that relational tables impose a strict schema, including column names and constraints, which is the definition of structured data. JSON is equally misclassified as structured because it permits nested, varying keys and does not require a predefined table format, making it semi-structured. A JPEG image contains pixel bytes and optional EXIF metadata, but no structured records, so semi-structured is wrong; it is unstructured. This option swaps all three categories incorrectly.

  When this WOULD be correct

  If the question asked to classify data types from least structured to most structured, then Unstructured (customer table) would be wrong, but if the customer table were actually a NoSQL key-value store and JSON had a fixed schema enforced by a validator, then JSON could be considered structured and JPEG semi-structured (e.g., if JPEGs had embedded metadata tags).

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The DP-900 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official DP-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

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