Enum PlanNode 

pub enum PlanNode {
    Scan {
        alias: String,
        resource_type: String,
    },
    LateralUnnest {
        parent: Box<PlanNode>,
        source: SqlExpr,
        out_alias: String,
        left_join: bool,
        on_filter: Option<SqlExpr>,
        flat_index: Option<i64>,
    },
    Filter {
        parent: Box<PlanNode>,
        predicate: SqlExpr,
    },
    Project {
        parent: Box<PlanNode>,
        columns: Vec<Column>,
    },
    Union(Vec<PlanNode>),
    Recurse {
        parent: Box<PlanNode>,
        seed: SqlExpr,
        step_paths: Vec<JsonPath>,
        out_alias: String,
    },
}

Row-source plan node.

Plans are trees: a Project at the root, descending through filters and lateral unnests to a Scan over resources. Union and Recurse wrap multiple sub-plans.

Variants

Scan

Top-level scan over the resources table for a single resource type. The tenant predicate is injected by the emitter.

Fields

alias: String

SQL alias for the scanned row (e.g., r).

resource_type: String

FHIR resource type to scan.

LateralUnnest

Lateral unnest of a JSON-array source. out_alias names the iteration row; left_join distinguishes forEach from forEachOrNull. on_filter, if set, is appended to the JOIN ON clause and lets a trailing where(crit) on the forEach path filter rows in-place (preserving LEFT JOIN semantics for forEachOrNull). flat_index, if set, restricts the unnest to the Nth element of the flattened collection (FHIRPath name[0] style indexing applied to the result of an array-flattening navigation).

Fields

parent: Box<PlanNode>

Plan whose rows are being unnested.

source: SqlExpr

JSON-array source expression.

out_alias: String

SQL alias bound to each iteration row.

left_join: bool

True for forEachOrNull (LEFT JOIN), false for forEach (INNER JOIN).

on_filter: Option<SqlExpr>

Optional filter appended to the JOIN ON clause.

flat_index: Option<i64>

When set, restrict the unnest to the Nth element of the flattened collection.

Filter

WHERE filter applied to parent. Multiple Filter nodes compose AND-wise.

Fields

parent: Box<PlanNode>

Plan whose rows are being filtered.

predicate: SqlExpr

Boolean predicate the rows must satisfy.

Project

Output projection.

Fields

parent: Box<PlanNode>

Plan supplying the rows to project.

columns: Vec<Column>

Output column definitions.

Union(Vec<PlanNode>)

UNION ALL of N row-compatible plans. Output schemas must align; the emitter validates this and emits a single ORDER BY 1 outside the compound query.

Recurse

Recursive-CTE descent — used for SoF repeat: clauses.

Fields

parent: Box<PlanNode>

Plan producing the seed rows.

seed: SqlExpr

Seed projection (currently unused; emitter walks parent).

step_paths: Vec<JsonPath>

Paths walked on each iteration.

out_alias: String

CTE alias also used as the node column alias.

Trait Implementations

impl Clone for PlanNode

fn clone(&self) -> PlanNode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PlanNode

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

Formats the value using the given formatter.