QuestDB is an open-source SQL database designed to process time-series data, faster.

It uses a column-oriented approach, vectorized execution, SIMD instructions, and a whole array of low-latency techniques. The whole code base is built from scratch and without dependencies, in the name of performance. QuestDB is 100% free from garbage collection.

QuestDB implements SQL, and augments it for time-series. It exposes a Postgres wire protocol, a high-performance REST API, and even supports ingestion with InfluxDB line protocol. It supports both relational and time-series joins, which makes it easy to correlate data over time. Writes are durably committed to disk, meaning that the data is safe - yet instantly accessible.


QuestDB was born as a side project from Vlad Ilyushchenko who applied principles from low latency techniques found in the financial services industry. QuestDB is backed by YCombinator and its recent Hacker News launch goes through the story of QuestDB since 2013.


Hash Join Semi Join

QuestDB supports the following types of joins: INNER, OUTER, CROSS, ASOF and SPLICE. FULL joins are not yet implemented and are on our roadmap. All supported join types can be combined in a single SQL statement.


Not Supported

Concurrency Control

Timestamp Ordering

QuestDB uses a single writer model. The writer re-orders timestamps on the fly. Multi-publisher, single consumer queue provides concurrent write access.

Storage Model

Decomposition Storage Model (Columnar)

QuestDB uses a column-based storage model. Data is stored in tables with each column stored in its own file and its own native format. New data is appended to the bottom of each column to allow data to be organically retrieved in the same order that it was ingested.

Parallel Execution

Inter-Operator (Vertical)

Multi threaded SQL execution.

Data Model

Column Family / Wide-Column Relational

QuestDB uses a relational model with column-based storage model.


Hash Table

Indexing is available for symbol columns. Index support for other types will be added over time.

Storage Organization


Query Compilation

JIT Compilation

Foreign Keys

Not Supported

Query Interface


QuestDB enhances ANSI SQL with time series extensions to manipulate time stamped data.

Storage Architecture


Memory mapped files data access.

System Architecture

Shared-Nothing Embedded

Stored Procedures

Not Supported

Hardware Acceleration


SIMD optimised analytics.

QuestDB Logo

Source Code

Tech Docs



Country of Origin


Start Year


Project Type

Commercial, Open Source

Written in

C++, Java

Supported languages

C, C++, Go, Java, JavaScript, Python, R, Rust, SQL

Inspired By


Compatible With

InfluxDB, PostgreSQL

Operating Systems

Android, Linux, OS X, Windows


Apache v2