Significant terms aggregation

Significant terms aggregation #

A multi-bucket aggregation returning terms that are unusually frequent in the current scope (foreground) compared with the whole index (background) — the classic “what’s special about this subset” query.

In this engine significant_terms currently approximates that idea by foreground frequency: it ranks the scope’s values by their in-scope doc_count, without computing background statistics. Nest it under a query or a parent bucket to scope the foreground set; the values that dominate that scope come out on top.