Crate datafusion_expr

Expand description

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;
pub use expr_fn::*;
pub use logical_plan::*;

Modules§

aggregate_doc_sections
binary: Coercion rules for matching argument types for binary operators
conditional_expressions: Conditional expressions
execution_props
expr: Logical Expressions: Expr
expr_fn: Functions for creating logical expressions
expr_rewriter: Expression rewriter
expr_schema
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
registry: FunctionRegistry trait
scalar_doc_sections
simplify: Structs and traits to provide the information needed for expression simplification.
sort_properties
test
tree_node: Tree node implementation for Logical Expressions
type_coercion: Type coercion rules for DataFusion
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.
ReturnInfo: Return metadata for this function.
ReturnTypeArgs: 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: Defines the supported argument types (TypeSignature) and Volatility for a function.
StatisticsArgs: Arguments passed to AggregateUDFImpl::value_from_stats
WindowUDF: Logical representation of a user-defined window function (UDWF).

Enums§

ArrayFunctionSignature
ColumnarValue: The result of evaluating an expression.
EmitTo: Describes how many rows should be emitted during grouping.
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: A function’s type signature defines the types of arguments the function supports.
TypeSignatureClass: Represents the class of types that can be used in a function signature.
Volatility: A function’s volatility, which defines the functions eligibility for certain optimizations

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.
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: Access schema information and filter push-down capabilities.
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

Type Aliases§

AccumulatorFactoryFunction: Factory that returns an accumulator for the given aggregate function.

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