Struct datafusion_optimizer::eliminate_cross_join::EliminateCrossJoin

pub struct EliminateCrossJoin;

Implementations

impl EliminateCrossJoin

pub fn new() -> Self

Trait Implementations

impl Default for EliminateCrossJoin

fn default() -> EliminateCrossJoin

Returns the “default value” for a type.

impl OptimizerRule for EliminateCrossJoin

Attempt to reorder join to eliminate cross joins to inner joins. for queries: ‘select … from a, b where a.x = b.y and b.xx = 100;’ ‘select … from a, b where (a.x = b.y and b.xx = 100) or (a.x = b.y and b.xx = 200);’ ‘select … from a, b, c where (a.x = b.y and b.xx = 100 and a.z = c.z) or (a.x = b.y and b.xx = 200 and a.z=c.z);’ For above queries, the join predicate is available in filters and they are moved to join nodes appropriately This fix helps to improve the performance of TPCH Q19. issue#78

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.