Module datafusion_expr::utils

Expression utilities

Constants

• COUNT_STAR_EXPANSION
  The value to which COUNT(*) is expanded to in COUNT(<constant>) expressions

Functions

• add_filter
  returns a new LogicalPlan that wraps plan in a LogicalPlan::Filter with its predicate be all predicates ANDed.
• can_hash
  can this data type be used in hash join equal conditions?? data types here come from function ‘equal_rows’, if more data types are supported in equal_rows(hash join), add those data types here to generate join logical plan.
• check_all_columns_from_schema
  Check whether all columns are from the schema.
• columnize_expr
  Convert an expression into Column expression if it’s already provided as input plan.
• compare_sort_expr
  Compare the sort expr as PostgreSQL’s common_prefix_cmp(): https://github.com/postgres/postgres/blob/master/src/backend/optimizer/plan/planner.c
• conjunction
  Combines an array of filter expressions into a single filter expression consisting of the input filter expressions joined with logical AND.
• disjunction
  Combines an array of filter expressions into a single filter expression consisting of the input filter expressions joined with logical OR.
• enumerate_grouping_sets
  Convert multiple grouping expressions into one GroupingSet::GroupingSets,
  if the grouping expression does not contain Expr::GroupingSet or only has one expression,
  no conversion will be performed.
• expand_qualified_wildcard
  Resolves an Expr::Wildcard to a collection of qualified Expr::Column’s.
• expand_wildcard
  Resolves an Expr::Wildcard to a collection of Expr::Column’s.
• expr_as_column_expr
  Convert any Expr to an Expr::Column.
• expr_to_columns
  Recursively walk an expression tree, collecting the unique set of columns referenced in the expression
• exprlist_to_columns
  Recursively walk a list of expression trees, collecting the unique set of columns referenced in the expression
• exprlist_to_fields
  Create field meta-data from an expression, for use in a result set schema
• find_aggregate_exprs
  Collect all deeply nested Expr::AggregateFunction. They are returned in order of occurrence (depth first), with duplicates omitted.
• find_column_exprs
  Collect all deeply nested Expr::Column’s. They are returned in order of appearance (depth first), and may contain duplicates.
• find_join_exprs
  Looks for correlating expressions: for example, a binary expression with one field from the subquery, and one not in the subquery (closed upon from outer scope)
• find_out_reference_exprs
  Collect all deeply nested Expr::OuterReferenceColumn. They are returned in order of occurrence (depth first), with duplicates omitted.
• find_sort_exprs
  Collect all deeply nested Expr::Sort. They are returned in order of occurrence (depth first), with duplicates omitted.
• find_valid_equijoin_key_pair
  Give two sides of the equijoin predicate, return a valid join key pair. If there is no valid join key pair, return None.
• find_window_exprs
  Collect all deeply nested Expr::WindowFunction. They are returned in order of occurrence (depth first), with duplicates omitted.
• from_planDeprecated
  Returns a new logical plan based on the original one with inputs and expressions replaced.
• generate_signature_error_msg
  Creates a detailed error message for a function with wrong signature.
• generate_sort_key
  Generate a sort key for a given window expr’s partition_by and order_bu expr
• group_window_expr_by_sort_keys
  group a slice of window expression expr by their order by expressions
• grouping_set_expr_count
  Count the number of distinct exprs in a list of group by expressions. If the first element is a GroupingSet expression then it must be the only expr.
• grouping_set_to_exprlist
  Find all distinct exprs in a list of group by expressions. If the first element is a GroupingSet expression then it must be the only expr.
• inspect_expr_pre
  Recursively inspect an Expr and all its children.
• merge_schema
  merge inputs schema into a single schema.
• only_or_err
  Returns the first (and only) element in a slice, or an error
• split_binary
  Splits an binary operator tree Expr such as A <OP> B <OP> C => [A, B, C]
• split_binary_owned
  Splits an owned binary operator tree Expr such as A <OP> B <OP> C => [A, B, C]
• split_conjunction
  Splits a conjunctive Expr such as A AND B AND C => [A, B, C]
• split_conjunction_owned
  Splits an owned conjunctive Expr such as A AND B AND C => [A, B, C]