SereneDB

SereneDB is an open-source database built for real-time search analytics, combining full-text search, vector search, and OLAP-style aggregations in a single engine. It is licensed under Apache 2.0 and developed by a team with deep expertise in databases, distributed systems, and information retrieval. The project launched its "Krummelanke" release in September 2026, positioning itself as a high-performance alternative to running Elasticsearch and ClickHouse separately.

What It Is

SereneDB is a search-OLAP database that lets developers run full-text search, vector search, hybrid search, and analytical aggregations over the same tables using standard SQL. It exposes the PostgreSQL wire protocol (v3.0 on port 7890), so most existing Postgres clients, drivers, and tools connect without code changes. The core search engine is powered by IResearch, an open-source C++ information retrieval library that core team members have been developing since 2016.

How the Engine Works

Three components underpin all eleven documented use cases:

• One SQL engine: Tables, joins, aggregates, and window functions in a dialect that closely follows PostgreSQL.
• One inverted index: A single CREATE INDEX … USING inverted covers analyzed text, verbatim and range fields, IVF vectors, and geospatial data. A query may constrain any subset of those fields in one statement.
• The Postgres wire protocol: Protocol v3.0 on port 7890 enables compatibility with most PostgreSQL clients and tooling.

The index refreshes every second by default (or on VACUUM (REFRESH_TABLE)), making new rows searchable in near real-time without a nightly batch job.

Use Cases and Workloads

SereneDB covers three groups of workloads:

• Search: Full-text search with BM25 ranking (nine scorers), vector search with IVF indexes (L2, cosine, inner-product, L1), hybrid search combining BM25 and vector scores via Reciprocal Rank Fusion, and Postgres-compatible search using the @@ operator.
• Analytics & data: Real-time aggregations, OLAP queries with vectorized columnar scans, search over data lakes (Parquet, CSV, JSON, ORC, Iceberg on disk or S3), and zero-ETL search that queries remote PostgreSQL or ClickHouse sources in place via CREATE SERVER.
• AI & agents: Agent-ready SQL scoped with GRANT, a RAG database with a langchain-serenedb LangChain VectorStore integration, and documentation search that indexes Git repos, folders, websites, or S3 buckets with an optional MCP server.

Deployment Model and Tradeoffs

SereneDB ships as a single binary installable via Docker, a Linux install script, or pre-built .tar.gz and .deb packages. A desktop GUI client called SereneUI is available for macOS, Linux, and Windows. The project explicitly notes that the current single-node version has no replication, no failover, and no managed service — horizontal scalability and high availability are described as roadmap items for production deployments. The complete single-node version is and always will be Apache 2.0, per the project's stated philosophy.

Update: SereneDB v26.09.1.2 (Krummelanke Release)

The latest release is v26.09.1.2, published September 23, 2026, as part of the "Krummelanke" launch. The project's open benchmark, SearchBench, covers 92 search, aggregation, and join queries over log-shaped data at 100M, 1B, and 10B rows, with adapters for SereneDB, ClickHouse, Elasticsearch, OpenSearch, and ParadeDB published alongside results. The GitHub repository was created in August 2025 and has been actively developed since, with the last push recorded in late September 2026.