Struct PlannerContext 

pub struct PlannerContext { /* private fields */ }

Struct to store the states used by the Planner. The Planner will leverage the states to resolve CTEs, Views, subqueries and PREPARE statements. The states include Common Table Expression (CTE) provided with WITH clause and Parameter Data Types provided with PREPARE statement and the query schema of the outer query plan.

Cloning

Only the ctes are truly cloned when the PlannerContext is cloned. This helps resolve scoping issues of CTEs. By using cloning, a subquery can inherit CTEs from the outer query and can also define its own private CTEs without affecting the outer query.

Implementations

impl PlannerContext

pub fn new() -> Self

Create an empty PlannerContext

pub fn with_prepare_param_data_types( self, prepare_param_data_types: Vec<FieldRef>, ) -> Self

Update the PlannerContext with provided prepare_param_data_types

pub fn outer_queries_schemas(&self) -> &[DFSchemaRef]

Return the stack of outer relations’ schemas, the outer most relation are at the first entry

pub fn outer_schemas_iter(&self) -> impl Iterator<Item = &DFSchemaRef>

Return an iterator of the subquery relations’ schemas, innermost relation is returned first.

This order corresponds to the order of resolution when looking up column references in subqueries, which start from the innermost relation and then look up the outer relations one by one until a match is found or no more outer relation exist.

NOTE this is REVERSED order of Self::outer_queries_schemas

This is useful to resolve the column reference in the subquery by looking up the outer query schemas one by one.

pub fn append_outer_query_schema(&mut self, schema: DFSchemaRef)

Sets the outer query schema, returning the existing one, if any

pub fn latest_outer_query_schema(&self) -> Option<&DFSchemaRef>

The schema of the adjacent outer relation

pub fn pop_outer_query_schema(&mut self) -> Option<DFSchemaRef>

Remove the schema of the adjacent outer relation

pub fn set_table_schema( &mut self, schema: Option<DFSchemaRef>, ) -> Option<DFSchemaRef>

pub fn table_schema(&self) -> Option<DFSchemaRef>

pub fn outer_from_schema(&self) -> Option<Arc<DFSchema>>

pub fn set_outer_from_schema( &mut self, schema: Option<DFSchemaRef>, ) -> Option<DFSchemaRef>

Sets the outer FROM schema, returning the existing one, if any

pub fn extend_outer_from_schema(&mut self, schema: &DFSchemaRef) -> Result<()>

Extends the FROM schema, returning the existing one, if any

pub fn prepare_param_data_types(&self) -> &[FieldRef]

Return the types of parameters ($1, $2, etc) if known

pub fn contains_cte(&self, cte_name: &str) -> bool

Returns true if there is a Common Table Expression (CTE) / Subquery for the specified name

pub fn insert_cte(&mut self, cte_name: impl Into<String>, plan: LogicalPlan)

Inserts a LogicalPlan for the Common Table Expression (CTE) / Subquery for the specified name

pub fn get_cte(&self, cte_name: &str) -> Option<&LogicalPlan>

Return a plan for the Common Table Expression (CTE) / Subquery for the specified name

Trait Implementations

impl Clone for PlannerContext

fn clone(&self) -> PlannerContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PlannerContext

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

Formats the value using the given formatter.

impl Default for PlannerContext

fn default() -> Self

Returns the “default value” for a type.