Crate datafusion_expr 

DataFusion is an extensible query execution framework that uses Apache Arrow as its in-memory format.

This crate is a submodule of DataFusion that provides types representing logical query plans (LogicalPlan) and logical expressions (Expr) as well as utilities for working with these types.

The expr_fn module contains functions for creating expressions.

Re-exports

pub use expr::Between;

pub use expr::BinaryExpr;

pub use expr::Case;

pub use expr::Cast;

pub use expr::Expr;

pub use expr::GetFieldAccess;

pub use expr::GroupingSet;

pub use expr::Like;

pub use expr::Sort as SortExpr;

pub use expr::TryCast;

pub use expr::WindowFunctionDefinition;

pub use expr_schema::ExprSchemable;

pub use function::PartitionEvaluatorFactory;

pub use function::ReturnTypeFunction;

pub use function::ScalarFunctionImplementation;

pub use function::StateTypeFunction;

pub use window_frame::WindowFrame;

pub use window_frame::WindowFrameBound;

pub use window_frame::WindowFrameUnits;

pub use sqlparser;sql

pub use expr_fn::*;

pub use logical_plan::*;

Modules

aggregate_doc_sections

arguments

Argument resolution logic for named function parameters

async_udf

binary

Coercion rules for matching argument types for binary operators

conditional_expressions

Conditional expressions

dml

DML (Data Manipulation Language) types for DELETE, UPDATE operations.

execution_props

expr

Logical Expressions: Expr

expr_fn

Functions for creating logical expressions

expr_rewriter

Expression rewriter

expr_schema

extension_types

This module contains code that enables DataFusion’s extension type capabilities.

function

Function module contains typing and signature for built-in and user defined functions.

groups_accumulator

interval_arithmetic

logical_plan

planner

ContextProvider and ExprPlanner APIs to customize SQL query planning

preimage

ptr_eq

registry

FunctionRegistry trait

scalar_doc_sections

select_expr

simplify

Structs to provide the information needed for expression simplification.

sort_properties

statistics

test

tree_node

Tree node implementation for Logical Expressions

type_coercion

Type coercion rules for DataFusion

udf_eq

utils

Expression utilities

var_provider

Variable provider

window_doc_sections

window_frame

Window frame module

window_state

Structures used to hold window function state (for implementing WindowUDFs)

Macros

expr_vec_fmt

Structs

AggregateUDF

Logical representation of a user-defined aggregate function (UDAF).

DocSection

Documentation

Documentation for use by ScalarUDFImpl, AggregateUDFImpl and WindowUDFImpl functions.

DocumentationBuilder

A builder for Documentation’s.

HigherOrderFunctionArgs

Arguments passed to HigherOrderUDFImpl::invoke_with_args when invoking a higher order function.

HigherOrderReturnFieldArgs

Information about arguments passed to the function

HigherOrderSignature

Provides information necessary for calling a higher order function.

HigherOrderUDF

Logical representation of a Higher Order User Defined Function.

LambdaArgument

A lambda argument to a HigherOrderFunction

ReturnFieldArgs

Information about arguments passed to the function

ScalarFunctionArgs

Arguments passed to ScalarUDFImpl::invoke_with_args when invoking a scalar function.

ScalarUDF

Logical representation of a Scalar User Defined Function.

Signature

Provides information necessary for calling a function.

StatisticsArgs

Arguments passed to AggregateUDFImpl::value_from_stats

StructFieldMapping

Describes how a struct-producing UDF’s output fields correspond to its input arguments. This enables the optimizer to propagate orderings through struct projections (e.g., so that sorting by a struct field can be recognized as equivalent to sorting by the source column).

WindowUDF

Logical representation of a user-defined window function (UDWF).

Enums

ArrayFunctionArgument

ArrayFunctionSignature

Coercion

Represents type coercion rules for function arguments, specifying both the desired type and optional implicit coercion rules for source types.

ColumnarValue

The result of evaluating an expression.

EmitTo

Describes how many rows should be emitted during grouping.

ExpressionPlacement

Describes where an expression should be placed in the query plan for optimal execution. This is used by optimizers to make decisions about expression placement, such as whether to push expressions down through projections.

HigherOrderTypeSignature

The types of arguments for which a function has implementations.

LambdaParametersProgress

Represents a step during the resolution of the parameters of all lambdas of a given higher-order function via HigherOrderUDFImpl::lambda_parameters. It’s valid that the fields of a given lambda changes between steps, and is up to the implementation to provide during the function evaluation the parameters that matches the fields returned at the LambdaParametersProgress::Complete step. See HigherOrderUDFImpl::lambda_parameters docs for more details

LimitEffect

the effect this function will have on the limit pushdown

Operator

Operators applied to expressions

ReversedUDAF

ReversedUDWF

SetMonotonicity

Indicates whether an aggregation function is monotonic as a set function. A set function is monotonically increasing if its value increases as its argument grows (as a set). Formally, f is a monotonically increasing set function if f(S) >= f(T) whenever S is a superset of T.

TableProviderFilterPushDown

Indicates how a filter expression is handled by TableProvider::scan.

TableType

Indicates the type of this table for metadata/catalog purposes.

TypeSignature

The types of arguments for which a function has implementations.

TypeSignatureClass

Represents the class of types that can be used in a function signature.

ValueOrLambda

An argument to a higher order function

Volatility

How a function’s output changes with respect to a fixed input

Constants

TIMEZONE_WILDCARD

Constant that is used as a placeholder for any valid timezone. This is used where a function can accept a timestamp type with any valid timezone, it exists to avoid the need to enumerate all possible timezones. See TypeSignature for more details.

Traits

Accumulator

Tracks an aggregate function’s state.

AggregateUDFImpl

Trait for implementing AggregateUDF.

GroupsAccumulator

GroupsAccumulator implements a single aggregate (e.g. AVG) and stores the state for all groups internally.

HigherOrderUDFImpl

Trait for implementing user defined higher order functions.

Literal

Trait for converting a type to a Literal literal expression.

PartitionEvaluator

Partition evaluator for Window Functions

ScalarUDFImpl

Trait for implementing user defined scalar functions.

TableSource

Planning time information about a table.

TimestampLiteral

Trait for converting a type to a literal timestamp

WindowUDFImpl

Trait for implementing WindowUDF.

Functions

lit

Create a literal expression

lit_timestamp_nano

Create a literal timestamp expression

lit_with_metadata

udaf_default_display_name

Encapsulates default implementation of AggregateUDFImpl::display_name.

udaf_default_human_display

Encapsulates default implementation of AggregateUDFImpl::human_display.

udaf_default_return_field

Encapsulates default implementation of AggregateUDFImpl::return_field.

udaf_default_schema_name

Encapsulates default implementation of AggregateUDFImpl::schema_name.

udaf_default_window_function_display_name

Encapsulates default implementation of AggregateUDFImpl::window_function_display_name.

udaf_default_window_function_schema_name

Encapsulates default implementation of AggregateUDFImpl::window_function_schema_name.

Type Aliases

AccumulatorFactoryFunction

Factory that returns an accumulator for the given aggregate function.