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dbms: Server: feature development [#METR-14875]

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This commit is contained in:
Alexey Arno 2015-02-12 00:54:58 +03:00
parent ef9a1c4388
commit dc296a4822
1 changed files with 47 additions and 37 deletions
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84
dbms/src/Interpreters/ExpressionAnalyzer.cpp
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@ -67,6 +67,8 @@ const std::unordered_set<String> injective_function_names
void ExpressionAnalyzer::init() void ExpressionAnalyzer::init()
{ {
optimizeOrChains();
select_query = typeid_cast<ASTSelectQuery *>(&*ast); select_query = typeid_cast<ASTSelectQuery *>(&*ast);
addStorageAliases(); addStorageAliases();
@ -77,8 +79,6 @@ void ExpressionAnalyzer::init()
/// Common subexpression elimination. Rewrite rules. /// Common subexpression elimination. Rewrite rules.
normalizeTree(); normalizeTree();
optimizeOrChains();
/// GROUP BY injective function elimination. /// GROUP BY injective function elimination.
optimizeGroupBy(); optimizeGroupBy();
@ -468,14 +468,14 @@ void ExpressionAnalyzer::normalizeTreeImpl(ASTPtr & ast, MapOfASTs & finished_as
struct OrWithIdentifier struct OrWithIdentifier
{ {
OrWithIdentifier(ASTFunction * or_function_, IAST * parent_, ASTIdentifier * identifier_) OrWithIdentifier(ASTFunction * or_function_, IAST * parent_, const std::string & identifier_)
: or_function(or_function_), parent(parent_), identifier(identifier_) : or_function(or_function_), parent(parent_), identifier(identifier_)
{ {
} }
ASTFunction * or_function; ASTFunction * or_function;
IAST * parent; IAST * parent;
ASTIdentifier * identifier; const std::string & identifier;
}; };
bool operator<(const OrWithIdentifier & lhs, const OrWithIdentifier & rhs) bool operator<(const OrWithIdentifier & lhs, const OrWithIdentifier & rhs)
@ -508,7 +508,8 @@ ASTFunctionPtr createInExpression(const OrWithIdentifier & or_with_identifier, c
ASTPtr value_list = new ASTExpressionList; ASTPtr value_list = new ASTExpressionList;
for (auto function : equal_function_list) for (auto function : equal_function_list)
{ {
auto literal = static_cast<ASTLiteral *>(&*(function->children[1])); auto expr = static_cast<ASTExpressionList *>(&*(function->children[0]));
auto literal = static_cast<ASTLiteral *>(&*(expr->children[1]));
value_list->children.push_back(literal->clone()); value_list->children.push_back(literal->clone());
} }
@ -517,7 +518,8 @@ ASTFunctionPtr createInExpression(const OrWithIdentifier & or_with_identifier, c
tuple_function->arguments = value_list; tuple_function->arguments = value_list;
tuple_function->children.push_back(tuple_function->arguments); tuple_function->children.push_back(tuple_function->arguments);
ASTPtr identifier = or_with_identifier.identifier->clone(); Poco::SharedPtr<ASTIdentifier> identifier = new ASTIdentifier;
identifier->name = or_with_identifier.identifier;
ASTPtr in_expr = new ASTExpressionList; ASTPtr in_expr = new ASTExpressionList;
in_expr->children.push_back(identifier); in_expr->children.push_back(identifier);
@ -556,36 +558,36 @@ void ExpressionAnalyzer::optimizeOrChains()
bool found = false; bool found = false;
ASTFunction * function = typeid_cast<ASTFunction *>(&*node); ASTFunction * function = typeid_cast<ASTFunction *>(&*node);
if ((function == nullptr) || (function->name != "or") || (function->children.size() != 1)) if ((function != nullptr) && (function->name == "or") && (function->children.size() == 1))
continue;
ASTExpressionList * expression_list = typeid_cast<ASTExpressionList *>(&*(function->children[0]));
if (expression_list == nullptr)
continue;
/// Цепочка элементов выражения OR.
for (auto child : expression_list->children)
{ {
ASTFunction * equals = typeid_cast<ASTFunction *>(&*child); ASTExpressionList * expression_list = typeid_cast<ASTExpressionList *>(&*(function->children[0]));
if ((equals == nullptr) || (equals->name != "equals") || (equals->children.size() != 1)) if (expression_list != nullptr)
continue; {
/// Цепочка элементов выражения OR.
ASTExpressionList * equals_expression_list = typeid_cast<ASTExpressionList *>(&*(equals->children[0])); for (auto child : expression_list->children)
if ((equals_expression_list == nullptr) || (equals_expression_list->children.size() != 2)) {
continue; ASTFunction * equals = typeid_cast<ASTFunction *>(&*child);
if ((equals != nullptr) && (equals->name == "equals") && (equals->children.size() == 1))
// Равенство c = xk {
ASTIdentifier * identifier = typeid_cast<ASTIdentifier *>(&*(equals_expression_list->children[0])); ASTExpressionList * equals_expression_list = typeid_cast<ASTExpressionList *>(&*(equals->children[0]));
if (identifier == nullptr) if ((equals_expression_list != nullptr) && (equals_expression_list->children.size() == 2))
continue; {
// Равенство c = xk
ASTLiteral * literal = typeid_cast<ASTLiteral *>(&*(equals_expression_list->children[1])); ASTIdentifier * identifier = typeid_cast<ASTIdentifier *>(&*(equals_expression_list->children[0]));
if (literal == nullptr) if (identifier != nullptr)
continue; {
ASTLiteral * literal = typeid_cast<ASTLiteral *>(&*(equals_expression_list->children[1]));
OrWithIdentifier pp(function, parent.get(), identifier); if (literal != nullptr)
equal_function_map[pp].push_back(equals); {
found = true; OrWithIdentifier pp(function, parent.get(), identifier->name);
equal_function_map[pp].push_back(equals);
found = true;
}
}
}
}
}
}
} }
if (!found) if (!found)
@ -614,10 +616,13 @@ void ExpressionAnalyzer::optimizeOrChains()
continue; continue;
bool check = true; bool check = true;
auto first_literal = static_cast<ASTLiteral *>(&*(equal_function_list[0]->children[1])); auto first_expr = static_cast<ASTExpressionList *>(&*(equal_function_list[0]->children[0]));
auto first_literal = static_cast<ASTLiteral *>(&*(first_expr->children[1]));
for (size_t i = 1; i < equal_function_list.size(); ++i) for (size_t i = 1; i < equal_function_list.size(); ++i)
{ {
auto literal = static_cast<ASTLiteral *>(&*(equal_function_list[i]->children[1])); auto expr = static_cast<ASTExpressionList *>(&*(equal_function_list[i]->children[0]));
auto literal = static_cast<ASTLiteral *>(&*(expr->children[1]));
if (literal->type != first_literal->type) if (literal->type != first_literal->type)
check = false; check = false;
} }
@ -662,6 +667,11 @@ void ExpressionAnalyzer::optimizeOrChains()
parent->children.push_back(children[0]); parent->children.push_back(children[0]);
auto it = std::remove(parent->children.begin(), parent->children.end(), or_function); auto it = std::remove(parent->children.begin(), parent->children.end(), or_function);
parent->children.erase(it, parent->children.end()); parent->children.erase(it, parent->children.end());
/// Если узел OR был корнем выражения WHERE, то следует обновить этот корень.
auto select = typeid_cast<ASTSelectQuery *>(&*ast);
if (or_function == select->where_expression.get())
select->where_expression = children[0];
} }
} }
} }