QuestDB is a high performance open source SQL database for time series data.

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

QuestDB implements SQL and augments it for time-series with native extensions. It exposes a Postgres wire protocol, high-performance REST API and supports ingestion with InfluxDB Line Protocol.


QuestDB started as a side project in 2013 by Vlad Ilyushchenko who applied principles from low latency techniques found in the financial services industry. QuestDB is backed by YCombinator.

Stored Procedures

Not Supported

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.

Query Interface


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

Query Compilation

JIT Compilation

Data Model


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

Storage Organization


Hardware Acceleration


SIMD optimised analytics.

Storage Architecture


Memory mapped files data access.

Foreign Keys

Not Supported


Hash Table

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

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.

Parallel Execution

Inter-Operator (Vertical)

Multi threaded SQL execution.


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

System Architecture

Shared-Nothing Embedded

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