Cassandra easy
What is the critical architectural function of the 'Partition Key' in a Cassandra table?
- A It determines the alphabetical sort order of data within a single file on the disk.
- B It is used by the 'Partitioner' to hash the value and decide which specific node in the cluster will store the row.
- C It serves as a backup key used only when the primary cluster experiences a total power failure.
- D It is an optional field used by administrators to tag data for manual backup purposes.
Answer: B. It is used by the 'Partitioner' to hash the value and decide which specific node in the cluster will store the row.
Cassandra hashes the Partition Key (e.g., `User_ID`) to a token using a partitioner (like Murmur3). That token determines exactly which node in the 'Ring' owns that data. This ensures that data is spread evenly across the cluster, preventing 'Hot Spots'.
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