QuestDB is an open-source time-series relational database. It uses a column-oriented approach and supports heavy parallelized vectorized execution using SIMD instructions. QuestDB implements a SQL interface and augments it with extensions simplifying the semantics of time-series queries. It supports high-throughput, schema-agnostic ingestion using the Postgres wire protocol and the InfluxDB line protocol. QuestDB is written from scratch in Java and C++ with no external dependencies and zero garbage collection.
- Website
- https://questdb.com/[01]
- Source Code
- https://github.com/questdb/questdb[02]
- Tech Docs
- https://questdb.com/docs/[03]
- Developer
- Country of Origin
- GB
- Start Year
- 2014 [05]
- Project Types
- Commercial, Open Source
- Inspired By
- Kdb+
- Compatible With
- InfluxDB, PostgreSQL
- License
- Apache v2
QuestDB is an open-source time-series relational database. It uses a column-oriented approach and supports heavy parallelized vectorized execution using SIMD instructions. QuestDB implements a SQL interface and augments it with extensions simplifying the semantics of time-series queries. It supports high-throughput, schema-agnostic ingestion using the Postgres wire protocol and the InfluxDB line protocol. QuestDB is written from scratch in Java and C++ with no external dependencies and zero garbage collection.
History[05][06]
QuestDB started as a side project in 2014 by Vlad Ilyushchenko who applied principles from low latency techniques found in the financial services industry. QuestDB is backed by YCombinator.
Concurrency Control[07]
QuestDB uses a single writer model. The writer re-orders timestamps on the fly. Multi-publisher, single consumer queue provides concurrent write access.
Indexes[09]
Indexing is available for symbol columns. The symbol datatype in QuestDB is used to store repeatitive strings. Internally, it is stored as a dictionary of integers and corresponding string values. The Index support for other types will be added over time.
Joins[10]
QuestDB supports INNER, LEFT OUTER, and CROSS join types. FULL joins are not yet implemented and are on our roadmap. In addition, QuestDB also supports ASOF, LT, and SPLICE join types particularly useful for time-series analytics.
Logging[11]
Starting from version 7.0, QuestDB supported using WAL to ingest data. With the addition of WAL-supported tables, clients can write to disk independently without holding the lock of the table writer. Transaction numbers are provided by a central sequencer protecting a single source of truth. After applying the WALs, the data is applied to the table asynchronously by another job.
Query Interface[13]
QuestDB enhances ANSI SQL with time series extensions to manipulate time stamped data.
Storage Model[08]
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.
Citations
14 sources- QuestDB | Low-latency time-series database on open formats questdb.com
- GitHub - questdb/questdb: QuestDB is a high performance, open-source, time-series database · GitHub github.com
- QuestDB Documentation - SQL Time-Series Database Guides | QuestDB questdb.com
- https://twitter.com/QuestDb twitter.com
- Initial commit github.com
- Launch HN: QuestDB (YC S20) – Fast open source time series database | Hacker News ycombinator.com
- Architecture Overview | QuestDB questdb.com
- Architecture Overview | QuestDB questdb.com
- Indexes | QuestDB questdb.com
- JOIN keyword | QuestDB questdb.com
- chore(core): WAL implementation by bluestreak01 · Pull Request #2144 · questdb/questdb · GitHub github.com
- Aggregating billions of rows per second with SIMD | QuestDB questdb.com
- https://questdb.com/docs/concept/sql-execution-order questdb.com
- Architecture Overview | QuestDB questdb.com