Struct ChildLink

pub struct ChildLink {
    pub child_index: Option<i32>,
    pub type_: Option<String>,
    pub variable: Option<String>,
}

Metadata associated with a parent-child relationship appearing in a PlanNode.

This type is not used in any activity, and only used as part of another schema.

Fields

child_index: Option<i32>

The node to which the link points.

type_: Option<String>

The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.

variable: Option<String>

Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a TableScan operator that reads rows from a table will have child links to the SCALAR nodes representing the output variables created for each column that is read by the operator. The corresponding variable fields will be set to the variable names assigned to the columns.

Trait Implementations

impl Clone for ChildLink

fn clone(&self) -> ChildLink

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChildLink

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

Formats the value using the given formatter.

impl Default for ChildLink

fn default() -> ChildLink

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ChildLink

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ChildLink

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Part for ChildLink