dbms: allowed constant expressions in IN [#METR-2944].

This commit is contained in:
Alexey Milovidov 2015-06-12 08:18:47 +03:00
parent 5b8008e2b1
commit a9becd36ea
3 changed files with 54 additions and 26 deletions

View File

@ -283,7 +283,7 @@ public:
* node - это список значений: 1, 2, 3 или список tuple-ов: (1, 2), (3, 4), (5, 6).
* create_ordered_set - создавать ли вектор упорядоченных элементов. Нужен для работы индекса
*/
void createFromAST(DataTypes & types, ASTPtr node, bool create_ordered_set);
void createFromAST(DataTypes & types, ASTPtr node, const Context & context, bool create_ordered_set);
// Возвращает false, если превышено какое-нибудь ограничение, и больше не нужно вставлять.
bool insertFromBlock(const Block & block, bool create_ordered_set = false);

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@ -954,7 +954,7 @@ void ExpressionAnalyzer::makeExplicitSet(ASTFunction * node, const Block & sampl
ASTPtr ast_set_ptr = ast_set;
ast_set->set = new Set(settings.limits);
ast_set->is_explicit = true;
ast_set->set->createFromAST(set_element_types, elements_ast, create_ordered_set);
ast_set->set->createFromAST(set_element_types, elements_ast, context, create_ordered_set);
arg = ast_set_ptr;
}

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@ -10,8 +10,12 @@
#include <DB/Parsers/ASTExpressionList.h>
#include <DB/Parsers/ASTFunction.h>
#include <DB/Parsers/ASTLiteral.h>
#include <DB/Parsers/formatAST.h>
#include <DB/Interpreters/Set.h>
#include <DB/Interpreters/ExpressionAnalyzer.h>
#include <DB/Interpreters/ExpressionActions.h>
#include <DB/DataTypes/DataTypeArray.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/DataTypes/DataTypeString.h>
@ -259,10 +263,10 @@ static Field convertToType(const Field & src, const IDataType & type)
if (is_uint8 || is_uint16 || is_uint32 || is_uint64)
{
if (src.getType() == Field::Types::Int64)
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, signed literal at right");
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, signed at right");
if (src.getType() == Field::Types::Float64)
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, floating point literal at right");
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, floating point at right");
if (src.getType() == Field::Types::UInt64)
{
@ -276,12 +280,12 @@ static Field convertToType(const Field & src, const IDataType & type)
}
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, "
+ Field::Types::toString(src.getType()) + " literal at right");
+ Field::Types::toString(src.getType()) + " at right");
}
else if (is_int8 || is_int16 || is_int32 || is_int64)
{
if (src.getType() == Field::Types::Float64)
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, floating point literal at right");
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, floating point at right");
if (src.getType() == Field::Types::UInt64)
{
@ -308,7 +312,7 @@ static Field convertToType(const Field & src, const IDataType & type)
}
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, "
+ Field::Types::toString(src.getType()) + " literal at right");
+ Field::Types::toString(src.getType()) + " at right");
}
else if (is_float32 || is_float64)
{
@ -322,7 +326,7 @@ static Field convertToType(const Field & src, const IDataType & type)
return src;
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, "
+ Field::Types::toString(src.getType()) + " literal at right");
+ Field::Types::toString(src.getType()) + " at right");
}
}
else
@ -337,22 +341,54 @@ static Field convertToType(const Field & src, const IDataType & type)
|| (src.getType() == Field::Types::Array
&& !typeid_cast<const DataTypeArray *>(&type)))
throw Exception("Type mismatch in IN section: " + type.getName() + " at left, "
+ Field::Types::toString(src.getType()) + " literal at right");
+ Field::Types::toString(src.getType()) + " at right");
}
return src;
}
void Set::createFromAST(DataTypes & types, ASTPtr node, bool create_ordered_set)
/** Выполнить константное выражение (для элемента множества в IN). Весьма неоптимально. */
static Field evaluateConstantExpression(ASTPtr & node, const Context & context)
{
/** NOTE:
* На данный момент в секции IN не поддерживаются выражения (вызовы функций), кроме кортежей.
* То есть, например, не поддерживаются массивы. А по хорошему, хотелось бы поддерживать.
* Для этого можно сделать constant folding с помощью ExpressionAnalyzer/ExpressionActions.
* Но при этом, конечно же, не забыть про производительность работы с крупными множествами.
*/
ExpressionActionsPtr expr_for_constant_folding = ExpressionAnalyzer(
node, context, NamesAndTypesList{{ "_dummy", new DataTypeUInt8 }}).getConstActions();
/// В блоке должен быть хотя бы один столбец, чтобы у него было известно число строк.
Block block_with_constants{{ new ColumnConstUInt8(1, 0), new DataTypeUInt8, "_dummy" }};
expr_for_constant_folding->execute(block_with_constants);
if (!block_with_constants || block_with_constants.rows() == 0)
throw Exception("Logical error: empty block after evaluation constant expression for IN", ErrorCodes::LOGICAL_ERROR);
String name = node->getColumnName();
if (!block_with_constants.has(name))
throw Exception("Element of set in IN is not a constant expression: " + name, ErrorCodes::BAD_ARGUMENTS);
const IColumn & result_column = *block_with_constants.getByName(name).column;
if (!result_column.isConst())
throw Exception("Element of set in IN is not a constant expression: " + name, ErrorCodes::BAD_ARGUMENTS);
return result_column[0];
}
static Field extractValueFromNode(ASTPtr & node, const IDataType & type, const Context & context)
{
if (ASTLiteral * lit = typeid_cast<ASTLiteral *>(node.get()))
return convertToType(lit->value, type);
else if (typeid_cast<ASTFunction *>(node.get()))
return convertToType(evaluateConstantExpression(node, context), type);
else
throw Exception("Incorrect element of set. Must be literal or constant expression.", ErrorCodes::INCORRECT_ELEMENT_OF_SET);
}
void Set::createFromAST(DataTypes & types, ASTPtr node, const Context & context, bool create_ordered_set)
{
data_types = types;
/// Засунем множество в блок.
@ -372,10 +408,7 @@ void Set::createFromAST(DataTypes & types, ASTPtr node, bool create_ordered_set)
{
if (data_types.size() == 1)
{
if (ASTLiteral * lit = typeid_cast<ASTLiteral *>(&**it))
block.getByPosition(0).column->insert(convertToType(lit->value, *data_types[0]));
else
throw Exception("Incorrect element of set. Must be literal.", ErrorCodes::INCORRECT_ELEMENT_OF_SET);
block.getByPosition(0).column->insert(extractValueFromNode(*it, *data_types[0], context));
}
else if (ASTFunction * func = typeid_cast<ASTFunction *>(&**it))
{
@ -388,16 +421,11 @@ void Set::createFromAST(DataTypes & types, ASTPtr node, bool create_ordered_set)
for (size_t j = 0; j < tuple_size; ++j)
{
if (ASTLiteral * lit = typeid_cast<ASTLiteral *>(&*func->arguments->children[j]))
block.getByPosition(j).column->insert(convertToType(lit->value, *data_types[j]));
else
throw Exception("Incorrect element of tuple in set. Must be literal.", ErrorCodes::INCORRECT_ELEMENT_OF_SET);
block.getByPosition(j).column->insert(extractValueFromNode(func->arguments->children[j], *data_types[j], context));
}
}
else
throw Exception("Incorrect element of set", ErrorCodes::INCORRECT_ELEMENT_OF_SET);
/// NOTE: Потом можно реализовать возможность задавать константные выражения в множествах.
}
if (create_ordered_set)