Global Index
Summary: A secondary index that covers data in all partitions, but is itself partitioned independently of the primary key; also known as a term-partitioned index.
Sources: chapter6
Last updated: 2026-04-15
Instead of each partition having its own local-index, we can construct a global index that covers data in all partitions. However, to avoid becoming a bottleneck, the global index itself must be partitioned. (source: chapter6)
Characteristics
- Reads: More efficient than local indexes because a client only needs to make a request to the partition containing the specific “term” (e.g., color:red) they are looking for. (source: chapter6)
- Writes: Slower and more complicated. A write to a single document may now affect multiple partitions of the index (every term in the document might be on a different partition). (source: chapter6)
- Consistency: Updates to global secondary indexes are often asynchronous in practice, meaning there might be a delay before a write is reflected in the index. (source: chapter6)