System Architect Go

Nov 17, 2020 · Big Data

Elasticsearch Distributed Search Mechanisms: query_then_fetch and dfs_query_then_fetch

Elasticsearch provides two search types—query_then_fetch (default) and dfs_query_then_fetch—each involving a multi-step process where the client node distributes queries to relevant shards, shards execute searches using local or global term frequencies, aggregate results, and retrieve full documents, with noted trade‑offs.