Struct SpjNormalForm 

pub struct SpjNormalForm { /* private fields */ }

A normalized representation of a plan containing only Select/Project/Join in the relational algebra sense. In DataFusion terminology this also includes Filter nodes. Joins are not currently supported, but are planned.

Implementations

impl SpjNormalForm

pub fn output_schema(&self) -> &Arc<DFSchema>

Schema of data output by this plan.

pub fn output_exprs(&self) -> &[Expr]

Expressions output by this plan. These expressions can be used to rewrite this plan as a cross join followed by a projection; however, this does not include any filters in the original plan, so the result will be a superset.

pub fn referenced_tables(&self) -> &[TableReference]

All tables referenced in this plan.

pub fn new(original_plan: &LogicalPlan) -> Result<Self>

Analyze an existing LogicalPlan and rewrite it in select-project-join normal form.

pub fn rewrite_from( &self, other: &Self, qualifier: TableReference, source: Arc<dyn TableSource>, ) -> Result<Option<LogicalPlan>>

Rewrite this plan as as selection/projection on top of another plan, which we use qualifier to refer to. This is useful for rewriting queries to use materialized views.

Trait Implementations

impl Clone for SpjNormalForm

fn clone(&self) -> SpjNormalForm

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SpjNormalForm

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

Formats the value using the given formatter.

impl TreeNodeRewriter for &SpjNormalForm

Rewrite an expression to re-use output columns from this plan, where possible.

type Node = Expr

The node type which is rewritable.

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

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.