Which description correctly contrasts schema-on-write with schema-on-read?
Show answer and explanation
Answer: D
With schema-on-write, data must conform to a defined structure when it is loaded, which is typical for relational databases. With schema-on-read, raw data is stored as-is and structure is applied when someone queries it, which is common in data lakes and many NoSQL systems. Relational tables are associated with schema-on-write, not schema-on-read.
Why the other options are wrong
- A. Schema-on-read does not impose structure before saving; it deliberately stores data without enforcing a schema at load time.
- B. Schema-on-write validates and shapes data at load time, so it does not defer interpretation until query execution.
- C. Schema-on-read is used by data lakes and many NoSQL systems, so restricting it to relational tables reverses the actual relationship.