Local Index
Summary: A secondary index that is partitioned in the same way as the primary data; also known as a document-partitioned index.
Sources: chapter6
Last updated: 2026-04-15
In this approach, each partition is completely separate: each partition maintains its own secondary indexes, covering only the documents in that partition. (source: chapter6)
Characteristics
- Writes: Very efficient. When you write to the database, you only need to deal with the partition that contains the document ID you are writing. (source: chapter6)
- Reads: Expensive. To find documents based on a secondary index, you must send the query to all partitions and combine the results. This is known as scatter/gather. (source: chapter6)
- Tail Latency: Scatter/gather is prone to tail latency amplification because the slowest partition determines the overall response time. (source: chapter6)