Struct RangeExprRewriter

pub struct RangeExprRewriter<'a> {
    input_plan: &'a Arc<LogicalPlan>,
    align: Duration,
    align_to: i64,
    by: Vec<Expr>,
    range_fn: BTreeSet<RangeFn>,
    sub_aggr: &'a Aggregate,
    query_ctx: &'a QueryContextRef,
}

RangeExprRewriter will recursively search certain Expr, find all range_fn scalar udf contained in Expr, and collect the information required by the RangeSelect query, and finally modify the range_fn scalar udf to an ordinary column field.

Fields

input_plan: &'a Arc<LogicalPlan>

align: Duration

align_to: i64

by: Vec<Expr>

range_fn: BTreeSet<RangeFn>

Use BTreeSet to avoid in case like avg(a) RANGE '5m' + avg(a) RANGE '5m', duplicate range expr avg(a) RANGE '5m' be calculate twice

sub_aggr: &'a Aggregate

query_ctx: &'a QueryContextRef

Implementations

impl RangeExprRewriter<'_>

pub fn get_range_expr(&self, args: &[Expr], i: usize) -> DFResult<Expr>

Trait Implementations

impl TreeNodeRewriter for RangeExprRewriter<'_>

type Node = Expr

The node type which is rewritable.

fn f_down(&mut self, node: Expr) -> DFResult<Transformed<Expr>>

Invoked while traversing down the tree before any children are rewritten. Default implementation returns the node as is and continues recursion.

fn f_up( &mut self, node: Self::Node, ) -> Result<Transformed<Self::Node>, DataFusionError>

Invoked while traversing up the tree after all children have been rewritten. Default implementation returns the node as is and continues recursion.