FugueSQL
Contents
FugueSQL#
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FugueSQL
is designed for heavy SQL users to extend the boundaries of traditional SQL workflows. FugueSQL
allows the expression of logic for end-to-end distributed computing workflows. It can also be combined with Python code to use custom functions alongside the SQL commands. It provides a unified interface, allowing the same SQL code to run on Pandas, Dask, and Spark.
The SQL code is parsed with ANTLR and mapped to the equivalent functions in the Fugue
programming interface.
FugueSQL has a 10 minute tutorial here. This page is a more in-depth look at FugueSQL.
1. Installation#
In order to use FugueSQL
, you first need to make sure you have installed the sql
extra
pip install fugue[sql]
To run on Spark or Dask execution engines, install the appropriate extras. Alternatively, all
can be used as an extra.
pip install fugue[sql, spark]
pip install fugue[sql, dask]
pip install fugue[all]
FugueSQL has a notebook extension for both Jupyter Notebooks and JupyterLab. This extension provides syntax highlighting and registers the %%fql
cell magic. To install the extension, use pip:
pip install fugue-jupyter
and then to register the startup script:
fugue-jupyter install startup
2. FugueSQL Syntax#
Get started with FugueSQL
. This shows input and output of data, enhancements over standard SQL, and how to use SQL to describe computation logic. After this, users will be able to use FugueSQL
with the familiar SQL keywords to perform operations on top of Pandas, Spark, and Dask.
3. Additional SQL Operators#
Go over the implemented operations that Fugue
has on top of the ones provided by standard SQL. FugueSQL
is extensible with Python code, but the most common functions are added as built-ins. These include filling NULL values, dropping NULL values, renaming columns, changing schema, etc. This section goes over the most used additional keywords.
4. Integrating Python#
Explore Jinja templating for variable passing, and using a Python functions as a Transformer in a %%fsql
cell.
5. Using Custom Fugue Extensions#
The Transformer is just one of many possible Fugue extensions. In this section we’ll explore the syntax of all the other Fugue extensions: Creator, Processor, Outputter, and CoTransformer.
6. Using Built-in Extensions#
Commonly used extensions are also provided as built-in extensions. These are also a good way to contribute to Fugue to enhance the FugueSQL experience.
7. FugueSQL with Pandas#
%%fsql
takes in the NativeExecutionEngine as a default parameter. This engine runs on Pandas. All of the SQL operations have equivalents in Pandas, but the behavior can be inconsistent sometimes. For example, Pandas will drop NULL values by default in a groupby operation. The NativeExecutionEngine was designed to mostly make operations consistent with Spark and SQL.
8. FugueSQL with Spark#
FugueSQL
also works on Spark by passing in the execution engine. This looks like %%fsql spark
. The operations are mapped to Spark and Spark SQL operations. The difference is FugueSQL
has added functionality for syntax compared to SparkSQL as seen in the syntax tutorial. Additionally with FugueSQL
, the same code will execute on Pandas and Dask without modification. This allows for quick testing without having to spin up a cluster. Users prototype with the NativeExecutionEngine
, and then move to the Spark cluster by changing the execution engine.