DataFusion is an extensible query engine written in Rust that uses Apache Arrow as its in-memory format.



Apache DataFusion

# Functions[#](https://datafusion.apache.org/library-user-guide/functions/index.html#functions "Link to this heading")

- [Adding User Defined Functions: Scalar/Window/Aggregate/Table Functions](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html)
  
  - [Adding a Scalar UDF](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#adding-a-scalar-udf)
  - [Adding an Async Scalar UDF](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#adding-an-async-scalar-udf)
  - [Named Arguments](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#named-arguments)
  - [Adding a Window UDF](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#adding-a-window-udf)
  - [Adding an Aggregate UDF](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#adding-an-aggregate-udf)
  - [Adding a Table UDF](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#adding-a-table-udf)
  - [Custom Expression Planning](https://datafusion.apache.org/library-user-guide/functions/adding-udfs.html#custom-expression-planning)
- [Spark Compatible Functions](https://datafusion.apache.org/library-user-guide/functions/spark.html)

Functions

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Gentle Arrow Introduction

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Extensions List

Using the SQL API

Extending SQL Syntax

Working with Exprs

Using the DataFrame API

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Adding User Defined Functions: Scalar/Window/Aggregate/Table Functions

Spark Compatible Functions

Custom Table Provider

Table Constraint Enforcement

Extending Operators

Profiling Cookbook

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GSoC Application Guidelines (2025)

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Functions

Functions#

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