Struct datafusion_optimizer::single_distinct_to_groupby::SingleDistinctToGroupBy

pub struct SingleDistinctToGroupBy {}

single distinct to group by optimizer rule

  SELECT F1(DISTINCT s),F2(DISTINCT s)
  ...
  GROUP BY k

  Into

  SELECT F1(alias1),F2(alias1)
  FROM (
    SELECT s as alias1, k ... GROUP BY s, k
  )
  GROUP BY k

Implementations

impl SingleDistinctToGroupBy

pub fn new() -> Self

Trait Implementations

impl Default for SingleDistinctToGroupBy

fn default() -> SingleDistinctToGroupBy

Returns the “default value” for a type.

impl OptimizerRule for SingleDistinctToGroupBy

fn try_optimize( &self, plan: &LogicalPlan, _config: &dyn OptimizerConfig ) -> Result<Option<LogicalPlan>>

Try and rewrite plan to an optimized form, returning None if the plan cannot be optimized by this rule.

fn name(&self) -> &str

A human readable name for this optimizer rule

fn apply_order(&self) -> Option<ApplyOrder>

How should the rule be applied by the optimizer? See comments on ApplyOrder for details.