A retail company stores three types of customer data: (1) a table with columns for CustomerID, Name, and Email; (2) product reviews as JSON documents with varying fields such as rating and comment; (3) product demonstration videos stored in MP4 format. Which of the following correctly classifies these data types in order from first to third?
Correct. The table is structured (fixed schema), JSON documents are semi-structured (flexible schema), and videos are unstructured (no schema).
Why this answer
The customer table with fixed columns (CustomerID, Name, Email) is structured data, product reviews as JSON documents with varying fields are semi-structured data (schema-on-read, flexible fields), and MP4 video files are unstructured data (no schema, binary format). This ordering matches the standard classification in Azure Data Fundamentals: structured → semi-structured → unstructured.
Exam trap
The trap here is that candidates often confuse semi-structured data (like JSON) with unstructured data, or assume all non-tabular data is unstructured, when in fact JSON's key-value pairs with varying fields make it semi-structured.
Why the other options are wrong
The first data type is a table with columns (CustomerID, Name, Email), which is structured, not unstructured. The second is JSON documents, which are semi-structured, not structured. The third is MP4 videos, which are unstructured, not semi-structured.
The order is incorrect because product reviews as JSON documents are semi-structured (not structured), and product demonstration videos are unstructured (not semi-structured). The correct order is structured (table), semi-structured (JSON), unstructured (video).
The order is incorrect: customer data in a table is structured, product reviews as JSON are semi-structured, and MP4 videos are unstructured. Option D reverses this order.