Module optimizer

re-export of datafusion_optimizer crate

Modules

• analyzer
  Analyzer and AnalyzerRule
• common_subexpr_eliminate
  CommonSubexprEliminate to avoid redundant computation of common sub-expressions
• decorrelate
  PullUpCorrelatedExpr converts correlated subqueries to Joins
• decorrelate_predicate_subquery
  DecorrelatePredicateSubquery converts IN/EXISTS subquery predicates to SEMI/ANTI joins
• eliminate_cross_join
  EliminateCrossJoin converts CROSS JOIN to INNER JOIN if join predicates are available.
• eliminate_duplicated_expr
  EliminateDuplicatedExpr Removes redundant expressions
• eliminate_filter
  EliminateFilter replaces where false or where null with an empty relation.
• eliminate_group_by_constant
  EliminateGroupByConstant removes constant expressions from GROUP BY clause
• eliminate_join
  EliminateJoin rewrites INNER JOIN with true/null
• eliminate_limit
  EliminateLimit eliminates LIMIT when possible
• eliminate_nested_union
  EliminateNestedUnion: flattens nested Union to a single Union
• eliminate_one_union
  EliminateOneUnion eliminates single element Union
• eliminate_outer_join
  EliminateOuterJoin converts LEFT/RIGHT/FULL joins to INNER joins
• extract_equijoin_predicate
  ExtractEquijoinPredicate identifies equality join (equijoin) predicates
• filter_null_join_keys
  FilterNullJoinKeys adds filters to join inputs when input isn’t nullable
• optimize_projections
  OptimizeProjections identifies and eliminates unused columns
• optimizer
  Optimizer and OptimizerRule
• propagate_empty_relation
  PropagateEmptyRelation eliminates nodes fed by EmptyRelation
• push_down_filter
  PushDownFilter applies filters as early as possible
• push_down_limit
  PushDownLimit pushes LIMIT earlier in the query plan
• replace_distinct_aggregate
  ReplaceDistinctWithAggregate replaces DISTINCT ... with GROUP BY ...
• scalar_subquery_to_join
  ScalarSubqueryToJoin rewriting scalar subquery filters to JOINs
• simplify_expressions
  SimplifyExpressions simplifies expressions in the logical plan, ExprSimplifier simplifies individual Exprs.
• single_distinct_to_groupby
  SingleDistinctToGroupBy replaces AGG(DISTINCT ..) with AGG(..) GROUP BY ..
• unwrap_cast_in_comparison
  UnwrapCastInComparison rewrites CAST(col) = lit to col = CAST(lit)
• utils
  Utility functions leveraged by the query optimizer rules

Structs

• Analyzer
  Rule-based Analyzer.
• Optimizer
  A rule-based optimizer.
• OptimizerContext
  A standalone OptimizerConfig that can be used independently of DataFusion’s config management

Traits

• AnalyzerRule
  AnalyzerRules transform LogicalPlans in some way to make the plan valid prior to the rest of the DataFusion optimization process.
• OptimizerConfig
  Options to control the DataFusion Optimizer.
• OptimizerRule
  OptimizerRules transforms one LogicalPlan into another which computes the same results, but in a potentially more efficient way. If there are no suitable transformations for the input plan, the optimizer should simply return it unmodified.

Functions

• optimize_childrenDeprecated
  Convenience rule for writing optimizers: recursively invoke optimize on plan’s children and then return a node of the same type. Useful for optimizer rules which want to leave the type of plan unchanged but still apply to the children. This also handles the case when the plan is a LogicalPlan::Explain.