Enum QueryNode 

pub enum QueryNode {
    Scan {
        predicate: String,
        estimated_rows: u64,
    },
    Filter {
        child: Box<QueryNode>,
        condition: String,
    },
    Join {
        left: Box<QueryNode>,
        right: Box<QueryNode>,
        join_key: String,
    },
    Project {
        child: Box<QueryNode>,
        fields: Vec<String>,
    },
    Limit {
        child: Box<QueryNode>,
        max_rows: u64,
    },
}

A node in a logical query plan.

Variants

Scan

Leaf table scan with an optional predicate string and cost hint.

Fields

predicate: String

estimated_rows: u64

Filter

Apply a boolean condition on top of a child plan.

Fields

child: Box<QueryNode>

condition: String

Join

Hash / nested-loop join on a single key.

Fields

left: Box<QueryNode>

right: Box<QueryNode>

join_key: String

Project

Column projection (field list).

Fields

child: Box<QueryNode>

fields: Vec<String>

Limit

Row-count cap.

Fields

child: Box<QueryNode>

max_rows: u64

Trait Implementations

impl Clone for QueryNode

fn clone(&self) -> QueryNode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QueryNode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for QueryNode

fn eq(&self, other: &QueryNode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for QueryNode