README.md

<h1 align="center">
  <img src="https://raw.githubusercontent.com/questdb/questdb/readme-improvements/core/src/main/resources/site/public/images/logo-readme.jpg"/>
</h1>

<p align="center">
  <a href="https://github.com/questdb/questdb/blob/master/LICENSE.txt"><img src="https://img.shields.io/github/license/questdb/questdb"></a>
  <a href="https://www.codacy.com/app/bluestreak/nfsdb"><img src="https://api.codacy.com/project/badge/grade/83c6250bd9fc45a98c12c191af710754"></a>
  <a href="https://circleci.com/gh/questdb/questdb"><img src="https://img.shields.io/circleci/build/github/questdb/questdb/master?token=c019f9fac8d84c0fa4896447d6073504a830e099"></a>
  <a href="https://serieux-saucisson-79115.herokuapp.com/"><img src="https://serieux-saucisson-79115.herokuapp.com/badge.svg"></a>
  <a href="https://github.com/questdb/questdb/releases/download/4.0.0/questdb-4.0.0-bin.tar.gz"><img src="https://img.shields.io/github/downloads/questdb/questdb/total"></a>
  <a href="https://search.maven.org/search?q=g:org.questdb"><img src="https://img.shields.io/maven-central/v/org.questdb/core"></a>
</p
  
<p/>

## What is QuestDB

QuestDB is a NewSQL database for Hybrid Transactional, Analytical and Time Series Processing workloads. QuestDB ingests data via HTTP, PostgresSQL wire protocol, Influx line protocol or directly from Java. Reading data is done using SQL via HTTP, PostgreSQL wire protocol or via Java API. The whole database is 3.5Mb packages.

## Project goals

- Treat time-series as first class citizen within a relational database.

- Be consistently economical and respectful of hardware resources. Don't waste CPU cycles, memory or storage.

- Be a reliable and trustworthy store of critical data.

- Low friction operation. Empower with SQL. Simplify every database interaction.

- Operate efficiently at both extremes: allow users to prioritise performance over data loss, or no loss over performance.

- Be both embedded and standalone.

## Building from source

### Pre-requitites:

- Java 8 64-bit. We recommend Oracle Java 8, but OpenJDK8 will also work (although a little slower).
- Maven 3
- Compatible 64-bit Operating System: Windows, Linux, OSX or ARM Linux
- Configure JAVA_HOME environment variable
- Add Maven "bin" directory to PATH environment variable

```
Note: Java versions above 8 are not yet supported. It is possible to build QuestDB with Java 11,
but this requires backward incompatible source code changes.
```

### Building

```
mvn clean package
```


### Running

Main class: `io.questdb.ServerMain`

Program arguments: `-d <home_directory>`

QuestDB will start HTTP server on 0:9000, which you can visit from your browser: http://localhost:9000. HTTP server is constrained by directory specified as program argument (-d). Additionally QuestDB will start PostgreSQL server on 0:8812, default login credentials are admin/quest. Both HTTP and PostresSQL server reference database in `home_directory/db`

## Getting Started

[Install](https://www.questdb.io/docs/install) and [run](https://www.questdb.io/docs/run) QuestDB.
Then, the easiest way to get started is to play with our
web [console](https://www.questdb.io/docs/console). This will allow you to import
and query data using an intuitive interface.

You may also take a look at our [storage model](https://www.questdb.io/docs/storagemodel). In a nutshell,
we are a column-oriented database, which partitions data by time intervals.

You can find more documentation [here](https://www.questdb.io/docs/documentation)

## Support / Contact

- [Slack Channel](https://join.slack.com/t/questdb/shared_invite/enQtNzk4Nzg4Mjc2MTE2LTEzZThjMzliMjUzMTBmYzVjYWNmM2UyNWJmNDdkMDYyZmE0ZDliZTQxN2EzNzk5MDE3Zjc1ZmJiZmFiZTIwMGY)

### Roadmap

We have built the ultimate performance for read and write on a single-thread.
But we still have some work to do.
Elements on our roadmap include:

- Query and aggregates optimisation. Currently, we run aggregates through linear scans.
While our scans are highly efficient, our current implementations of aggregates are somehow naive.
Further optimisation will take performance to new levels.
- Multithreading. Currently, we use one single thread. While this is good for certain use cases
(you can limit QuestDB to one thread and leave resources for other programs), we will provide
the ability to distribute load/query work over several cores to benefit from parallelisation.
- High-availability. Working on providing out-of-the-box high-availability with extreme simplicity.

### Contribution

Feel free to contribute to the project by forking the repository and submitting pull requests.
Please make sure you have read our [contributing guide](https://github.com/questdb/questdb/blob/master/CONTRIBUTING.md).