OmniSciDB  04ee39c94c
JoinCoveredQualVisitor Class Reference
+ Inheritance diagram for JoinCoveredQualVisitor:
+ Collaboration diagram for JoinCoveredQualVisitor:

Public Member Functions

 JoinCoveredQualVisitor (const JoinQualsPerNestingLevel &join_quals)
bool visitFunctionOper (const Analyzer::FunctionOper *func_oper) const override
bool defaultResult () const override
- Public Member Functions inherited from ScalarExprVisitor< bool >
bool visit (const Analyzer::Expr *expr) const

Private Attributes

std::vector< std::pair< const Analyzer::Expr *, const Analyzer::Expr * > > join_qual_pairs

Additional Inherited Members

- Protected Member Functions inherited from ScalarExprVisitor< bool >
virtual bool visitVar (const Analyzer::Var *) const
virtual bool visitColumnVar (const Analyzer::ColumnVar *) const
virtual bool visitColumnVarTuple (const Analyzer::ExpressionTuple *) const
virtual bool visitConstant (const Analyzer::Constant *) const
virtual bool visitUOper (const Analyzer::UOper *uoper) const
virtual bool visitBinOper (const Analyzer::BinOper *bin_oper) const
virtual bool visitInValues (const Analyzer::InValues *in_values) const
virtual bool visitInIntegerSet (const Analyzer::InIntegerSet *in_integer_set) const
virtual bool visitCharLength (const Analyzer::CharLengthExpr *char_length) const
virtual bool visitKeyForString (const Analyzer::KeyForStringExpr *key_for_string) const
virtual bool visitCardinality (const Analyzer::CardinalityExpr *cardinality) const
virtual bool visitLikeExpr (const Analyzer::LikeExpr *like) const
virtual bool visitRegexpExpr (const Analyzer::RegexpExpr *regexp) const
virtual bool visitCaseExpr (const Analyzer::CaseExpr *case_) const
virtual bool visitDatetruncExpr (const Analyzer::DatetruncExpr *datetrunc) const
virtual bool visitExtractExpr (const Analyzer::ExtractExpr *extract) const
virtual bool visitFunctionOperWithCustomTypeHandling (const Analyzer::FunctionOperWithCustomTypeHandling *func_oper) const
virtual bool visitArrayOper (Analyzer::ArrayExpr const *array_expr) const
virtual bool visitWindowFunction (const Analyzer::WindowFunction *window_func) const
virtual bool visitDatediffExpr (const Analyzer::DatediffExpr *datediff) const
virtual bool visitDateaddExpr (const Analyzer::DateaddExpr *dateadd) const
virtual bool visitLikelihood (const Analyzer::LikelihoodExpr *likelihood) const
virtual bool visitOffsetInFragment (const Analyzer::OffsetInFragment *) const
virtual bool visitAggExpr (const Analyzer::AggExpr *agg) const
virtual bool aggregateResult (const bool &aggregate, const bool &next_result) const

Detailed Description

JoinCoveredQualVisitor returns true if the visited qual is true if and only if a corresponding equijoin qual is true. During the pre-filtered count we can elide the visited qual decreasing query run time while upper bounding the number of rows passing the filter. Currently only used for expressions of the form a OVERLAPS b AND Expr<a, b>. Strips Expr<a,b> if the expression has been pre-determined to be expensive to compute twice.

Definition at line 765 of file ExpressionRewrite.cpp.

Constructor & Destructor Documentation

◆ JoinCoveredQualVisitor()

JoinCoveredQualVisitor::JoinCoveredQualVisitor ( const JoinQualsPerNestingLevel join_quals)

Definition at line 767 of file ExpressionRewrite.cpp.

767  {
768  for (const auto& join_condition : join_quals) {
769  for (const auto& qual : join_condition.quals) {
770  auto qual_bin_oper = dynamic_cast<Analyzer::BinOper*>(qual.get());
771  if (qual_bin_oper) {
772  join_qual_pairs.emplace_back(qual_bin_oper->get_left_operand(),
773  qual_bin_oper->get_right_operand());
774  }
775  }
776  }
777  }
std::vector< std::pair< const Analyzer::Expr *, const Analyzer::Expr * > > join_qual_pairs

Member Function Documentation

◆ defaultResult()

bool JoinCoveredQualVisitor::defaultResult ( ) const

Reimplemented from ScalarExprVisitor< bool >.

Definition at line 793 of file ExpressionRewrite.cpp.

793 { return false; }

◆ visitFunctionOper()

bool JoinCoveredQualVisitor::visitFunctionOper ( const Analyzer::FunctionOper func_oper) const

Reimplemented from ScalarExprVisitor< bool >.

Definition at line 779 of file ExpressionRewrite.cpp.

References Analyzer::FunctionOper::getArg(), Analyzer::FunctionOper::getName(), and anonymous_namespace{ExpressionRewrite.cpp}::overlaps_supported_functions.

779  {
780  if (overlaps_supported_functions.find(func_oper->getName()) !=
782  const auto lhs = func_oper->getArg(2);
783  const auto rhs = func_oper->getArg(1);
784  for (const auto qual_pair : join_qual_pairs) {
785  if (*lhs == *qual_pair.first && *rhs == *qual_pair.second) {
786  return true;
787  }
788  }
789  }
790  return false;
791  }
std::string getName() const
Definition: Analyzer.h:1250
const Analyzer::Expr * getArg(const size_t i) const
Definition: Analyzer.h:1254
static const std::unordered_set< std::string > overlaps_supported_functions
std::vector< std::pair< const Analyzer::Expr *, const Analyzer::Expr * > > join_qual_pairs
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Member Data Documentation

◆ join_qual_pairs

std::vector<std::pair<const Analyzer::Expr*, const Analyzer::Expr*> > JoinCoveredQualVisitor::join_qual_pairs

Definition at line 796 of file ExpressionRewrite.cpp.

The documentation for this class was generated from the following file: