DocumentDB 0.113 adds covering index support for $group aggregation pipeline

DocumentDB version 0.113, released on June 22, 2026, introduces an index-only access path for MongoDB-style $group aggregation queries within its PostgreSQL execution engine. DocumentDB is a fully open-source PostgreSQL extension that implements the MongoDB API, offering an open alternative for MongoDB applications. The new feature allows aggregation queries using $group and $sum to read directly from index entries rather than scanning full documents, improving query efficiency. In benchmark tests comparing versions 0.112 and 0.113 on a 10,000-row dataset, the updated version achieved zero documents examined while scanning only index keys. Microsoft is the primary contributor to the project, refining the extension based on enterprise customer feedback gathered through Azure DocumentDB.