datafusion_functions_aggregate/
lib.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
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17
18#![doc(
19    html_logo_url = "https://raw.githubusercontent.com/apache/datafusion/19fe44cf2f30cbdd63d4a4f52c74055163c6cc38/docs/logos/standalone_logo/logo_original.svg",
20    html_favicon_url = "https://raw.githubusercontent.com/apache/datafusion/19fe44cf2f30cbdd63d4a4f52c74055163c6cc38/docs/logos/standalone_logo/logo_original.svg"
21)]
22#![cfg_attr(docsrs, feature(doc_auto_cfg))]
23// Make cheap clones clear: https://github.com/apache/datafusion/issues/11143
24#![deny(clippy::clone_on_ref_ptr)]
25
26//! Aggregate Function packages for [DataFusion].
27//!
28//! This crate contains a collection of various aggregate function packages for DataFusion,
29//! implemented using the extension API. Users may wish to control which functions
30//! are available to control the binary size of their application as well as
31//! use dialect specific implementations of functions (e.g. Spark vs Postgres)
32//!
33//! Each package is implemented as a separate
34//! module, activated by a feature flag.
35//!
36//! [DataFusion]: https://crates.io/crates/datafusion
37//!
38//! # Available Packages
39//! See the list of [modules](#modules) in this crate for available packages.
40//!
41//! # Using A Package
42//! You can register all functions in all packages using the [`register_all`] function.
43//!
44//! Each package also exports an `expr_fn` submodule to help create [`Expr`]s that invoke
45//! functions using a fluent style. For example:
46//!
47//![`Expr`]: datafusion_expr::Expr
48//!
49//! # Implementing A New Package
50//!
51//! To add a new package to this crate, you should follow the model of existing
52//! packages. The high level steps are:
53//!
54//! 1. Create a new module with the appropriate [AggregateUDF] implementations.
55//!
56//! 2. Use the macros in [`macros`] to create standard entry points.
57//!
58//! 3. Add a new feature to `Cargo.toml`, with any optional dependencies
59//!
60//! 4. Use the `make_package!` macro to expose the module when the
61//!    feature is enabled.
62
63#[macro_use]
64pub mod macros;
65
66pub mod approx_distinct;
67pub mod approx_median;
68pub mod approx_percentile_cont;
69pub mod approx_percentile_cont_with_weight;
70pub mod array_agg;
71pub mod average;
72pub mod bit_and_or_xor;
73pub mod bool_and_or;
74pub mod correlation;
75pub mod count;
76pub mod covariance;
77pub mod first_last;
78pub mod grouping;
79pub mod hyperloglog;
80pub mod median;
81pub mod min_max;
82pub mod nth_value;
83pub mod regr;
84pub mod stddev;
85pub mod string_agg;
86pub mod sum;
87pub mod variance;
88
89pub mod planner;
90
91use crate::approx_percentile_cont::approx_percentile_cont_udaf;
92use crate::approx_percentile_cont_with_weight::approx_percentile_cont_with_weight_udaf;
93use datafusion_common::Result;
94use datafusion_execution::FunctionRegistry;
95use datafusion_expr::AggregateUDF;
96use log::debug;
97use std::sync::Arc;
98
99/// Fluent-style API for creating `Expr`s
100pub mod expr_fn {
101    pub use super::approx_distinct::approx_distinct;
102    pub use super::approx_median::approx_median;
103    pub use super::approx_percentile_cont::approx_percentile_cont;
104    pub use super::approx_percentile_cont_with_weight::approx_percentile_cont_with_weight;
105    pub use super::array_agg::array_agg;
106    pub use super::average::avg;
107    pub use super::bit_and_or_xor::bit_and;
108    pub use super::bit_and_or_xor::bit_or;
109    pub use super::bit_and_or_xor::bit_xor;
110    pub use super::bool_and_or::bool_and;
111    pub use super::bool_and_or::bool_or;
112    pub use super::correlation::corr;
113    pub use super::count::count;
114    pub use super::count::count_distinct;
115    pub use super::covariance::covar_pop;
116    pub use super::covariance::covar_samp;
117    pub use super::first_last::first_value;
118    pub use super::first_last::last_value;
119    pub use super::grouping::grouping;
120    pub use super::median::median;
121    pub use super::min_max::max;
122    pub use super::min_max::min;
123    pub use super::nth_value::nth_value;
124    pub use super::regr::regr_avgx;
125    pub use super::regr::regr_avgy;
126    pub use super::regr::regr_count;
127    pub use super::regr::regr_intercept;
128    pub use super::regr::regr_r2;
129    pub use super::regr::regr_slope;
130    pub use super::regr::regr_sxx;
131    pub use super::regr::regr_sxy;
132    pub use super::regr::regr_syy;
133    pub use super::stddev::stddev;
134    pub use super::stddev::stddev_pop;
135    pub use super::sum::sum;
136    pub use super::variance::var_pop;
137    pub use super::variance::var_sample;
138}
139
140/// Returns all default aggregate functions
141pub fn all_default_aggregate_functions() -> Vec<Arc<AggregateUDF>> {
142    vec![
143        array_agg::array_agg_udaf(),
144        first_last::first_value_udaf(),
145        first_last::last_value_udaf(),
146        covariance::covar_samp_udaf(),
147        covariance::covar_pop_udaf(),
148        correlation::corr_udaf(),
149        sum::sum_udaf(),
150        min_max::max_udaf(),
151        min_max::min_udaf(),
152        median::median_udaf(),
153        count::count_udaf(),
154        regr::regr_slope_udaf(),
155        regr::regr_intercept_udaf(),
156        regr::regr_count_udaf(),
157        regr::regr_r2_udaf(),
158        regr::regr_avgx_udaf(),
159        regr::regr_avgy_udaf(),
160        regr::regr_sxx_udaf(),
161        regr::regr_syy_udaf(),
162        regr::regr_sxy_udaf(),
163        variance::var_samp_udaf(),
164        variance::var_pop_udaf(),
165        stddev::stddev_udaf(),
166        stddev::stddev_pop_udaf(),
167        approx_median::approx_median_udaf(),
168        approx_distinct::approx_distinct_udaf(),
169        approx_percentile_cont_udaf(),
170        approx_percentile_cont_with_weight_udaf(),
171        string_agg::string_agg_udaf(),
172        bit_and_or_xor::bit_and_udaf(),
173        bit_and_or_xor::bit_or_udaf(),
174        bit_and_or_xor::bit_xor_udaf(),
175        bool_and_or::bool_and_udaf(),
176        bool_and_or::bool_or_udaf(),
177        average::avg_udaf(),
178        grouping::grouping_udaf(),
179        nth_value::nth_value_udaf(),
180    ]
181}
182
183/// Registers all enabled packages with a [`FunctionRegistry`]
184pub fn register_all(registry: &mut dyn FunctionRegistry) -> Result<()> {
185    let functions: Vec<Arc<AggregateUDF>> = all_default_aggregate_functions();
186
187    functions.into_iter().try_for_each(|udf| {
188        let existing_udaf = registry.register_udaf(udf)?;
189        if let Some(existing_udaf) = existing_udaf {
190            debug!("Overwrite existing UDAF: {}", existing_udaf.name());
191        }
192        Ok(()) as Result<()>
193    })?;
194
195    Ok(())
196}
197
198#[cfg(test)]
199mod tests {
200    use crate::all_default_aggregate_functions;
201    use datafusion_common::Result;
202    use std::collections::HashSet;
203
204    #[test]
205    fn test_no_duplicate_name() -> Result<()> {
206        let mut names = HashSet::new();
207        let migrated_functions = ["array_agg", "count", "max", "min"];
208        for func in all_default_aggregate_functions() {
209            // TODO: remove this
210            // These functions are in intermediate migration state, skip them
211            if migrated_functions.contains(&func.name().to_lowercase().as_str()) {
212                continue;
213            }
214            assert!(
215                names.insert(func.name().to_string().to_lowercase()),
216                "duplicate function name: {}",
217                func.name()
218            );
219            for alias in func.aliases() {
220                assert!(
221                    names.insert(alias.to_string().to_lowercase()),
222                    "duplicate function name: {}",
223                    alias
224                );
225            }
226        }
227        Ok(())
228    }
229}