Q2 Cosmos DB Domain 2 · 25–30% of exam

Which property in a Cosmos DB container controls how data is distributed across logical partitions?

  1. A Container ID
  2. B Primary key
  3. C Partition key (correct answer)
  4. D Sort key

Shortcut: The partition key determines how documents are grouped into logical partitions. Choosing a high-cardinality partition key (many distinct values) ensures even distribution of data and throughput.