Module datafusion::logical_expr

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Expand description

re-export of datafusion_expr crate

Modules§

Macros§

Structs§

Enums§

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.
  • UNNAMED_TABLE
    Default table name for unnamed table

Traits§

  • Accumulator
    Tracks an aggregate function’s state.
  • AggregateUDFImpl
    Trait for implementing AggregateUDF.
  • ExprSchemable
    trait to allow expr to typable with respect to a schema
  • GroupsAccumulator
    GroupAccumulator 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 ScalarUDF.
  • TableSource
    The TableSource trait is used during logical query planning and optimizations and provides access to schema information and filter push-down capabilities. This trait provides a subset of the functionality of the TableProvider trait in the core datafusion crate. The TableProvider trait provides additional capabilities needed for physical query execution (such as the ability to perform a scan). The reason for having two separate traits is to avoid having the logical plan code be dependent on the DataFusion execution engine. Other projects may want to use DataFusion’s logical plans and have their own execution engine.
  • TimestampLiteral
    Trait for converting a type to a literal timestamp
  • ToStringifiedPlan
    Trait for something that can be formatted as a stringified plan
  • UserDefinedLogicalNode
    This defines the interface for LogicalPlan nodes that can be used to extend DataFusion with custom relational operators.
  • UserDefinedLogicalNodeCore
    This trait facilitates implementation of the UserDefinedLogicalNode.
  • WindowUDFImpl
    Trait for implementing WindowUDF.

Functions§

  • and
    Return a new expression with a logical AND
  • approx_distinct
    Returns the approximate number of distinct input values. This function provides an approximation of count(DISTINCT x). Zero is returned if all input values are null. This function should produce a standard error of 0.81%, which is the standard deviation of the (approximately normal) error distribution over all possible sets. It does not guarantee an upper bound on the error for any specific input set.
  • approx_median
    Calculate an approximation of the median for expr.
  • approx_percentile_cont
    Calculate an approximation of the specified percentile for expr.
  • approx_percentile_cont_with_weight
    Calculate an approximation of the specified percentile for expr and weight_expr.
  • array_agg
    Create an expression to represent the array_agg() aggregate function
  • avg
    Create an expression to represent the avg() aggregate function
  • binary_expr
    Return a new expression left <op> right
  • bitwise_and
    Return a new expression with bitwise AND
  • bitwise_or
    Return a new expression with bitwise OR
  • bitwise_shift_left
    Return a new expression with bitwise SHIFT LEFT
  • bitwise_shift_right
    Return a new expression with bitwise SHIFT RIGHT
  • bitwise_xor
    Return a new expression with bitwise XOR
  • build_join_schema
    Creates a schema for a join operation. The fields from the left side are first
  • case
    Create a CASE WHEN statement with literal WHEN expressions for comparison to the base expression.
  • cast
    Create a cast expression
  • col
    Create a column expression based on a qualified or unqualified column name. Will normalize unquoted identifiers according to SQL rules (identifiers will become lowercase).
  • count
    Create an expression to represent the count() aggregate function
  • count_distinct
    Create an expression to represent the count(distinct) aggregate function
  • create_udaf
    Creates a new UDAF with a specific signature, state type and return type. The signature and state type must match the Accumulator's implementation.
  • create_udf
    Convenience method to create a new user defined scalar function (UDF) with a specific signature and specific return type.
  • create_udwf
    Creates a new UDWF with a specific signature, state type and return type.
  • cube
    Create a grouping set for all combination of exprs
  • display_schema
    Print the schema in a compact representation to buf
  • exists
    Create an EXISTS subquery expression
  • grouping_set
    Create a grouping set
  • ident
    Create an unqualified column expression from the provided name, without normalizing the column.
  • in_list
    Create an in_list expression
  • in_subquery
    Create an IN subquery expression
  • is_false
    Create is false expression
  • is_not_false
    Create is not false expression
  • is_not_true
    Create is not true expression
  • is_not_unknown
    Create is not unknown expression
  • is_null
    Create is null expression
  • is_true
    Create is true expression
  • is_unknown
    Create is unknown expression
  • lit
    Create a literal expression
  • lit_timestamp_nano
    Create a literal timestamp expression
  • max
    Create an expression to represent the max() aggregate function
  • median
    Calculate the median for expr.
  • min
    Create an expression to represent the min() aggregate function
  • not
    Return a new expression with a logical NOT
  • not_exists
    Create a NOT EXISTS subquery expression
  • not_in_subquery
    Create a NOT IN subquery expression
  • or
    Return a new expression with a logical OR
  • out_ref_col
    Create an out reference column which hold a reference that has been resolved to a field outside of the current plan.
  • placeholder
    Create placeholder value that will be filled in (such as $1)
  • projection_schema
    Computes the schema of the result produced by applying a projection to the input logical plan.
  • rollup
    Create a grouping set for rollup
  • scalar_subquery
    Create a scalar subquery expression
  • stddev
    Create an expression to represent the stddev() aggregate function
  • sum
    Create an expression to represent the sum() aggregate function
  • table_scan
    Create a LogicalPlanBuilder representing a scan of a table with the provided name and schema. This is mostly used for testing and documentation.
  • try_cast
    Create a try cast expression
  • union
    Union two logical plans.
  • when
    Create a CASE WHEN statement with boolean WHEN expressions and no base expression.
  • wildcard
    Create an ‘*’ Expr::Wildcard expression that matches all columns
  • wrap_projection_for_join_if_necessary
    Wrap projection for a plan, if the join keys contains normal expression.

Type Aliases§

  • AccumulatorFactoryFunction
    Factory that returns an accumulator for the given aggregate function.
  • FuncMonotonicity
    Monotonicity of the ScalarFunctionExpr with respect to its arguments. Each element of this vector corresponds to an argument and indicates whether the function’s behavior is monotonic, or non-monotonic/unknown for that argument, namely:
  • PartitionEvaluatorFactory
    Factory that creates a PartitionEvaluator for the given window function
  • ReturnTypeFunction
    Factory that returns the functions’s return type given the input argument types
  • ScalarFunctionImplementation
    Scalar function
  • StateTypeFunction
    Factory that returns the types used by an aggregator to serialize its state, given its return datatype.