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#include <Interpreters/OptimizeDateOrDateTimeConverterWithPreimageVisitor.h>
#include <Core/Field.h>
#include <Core/NamesAndTypes.h>
#include <Common/DateLUT.h>
#include <Common/DateLUTImpl.h>
#include <Functions/FunctionFactory.h>
#include <Interpreters/IdentifierSemantic.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/ASTFunction.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
/** Given a monotonic non-decreasing function f(x), which satisfies f(x) = c for any value x within [b, e).
* We could convert it into its equivalent form, x >= b AND x < e, which is free from the invocation of the function.
* And we could apply the similar transformation to other comparisons. The suggested transformations list:
*
* f(x) == c -> x >= b AND x < e
* f(x) != c -> x < b OR x >= e
* f(x) > c -> x >= e
* f(x) >= c -> x >= b
* f(x) < c -> x < b
* f(x) <= c -> x < e
*
* This function generates a new AST with the transformed relation.
*/
ASTPtr generateOptimizedDateFilterAST(const String & comparator, const NameAndTypePair & column, const std::pair<Field, Field>& range)
{
const DateLUTImpl & date_lut = DateLUT::instance("UTC");
const String & column_name = column.name;
String start_date_or_date_time;
String end_date_or_date_time;
if (isDateOrDate32(column.type.get()))
{
start_date_or_date_time = date_lut.dateToString(range.first.get<DateLUTImpl::Time>());
end_date_or_date_time = date_lut.dateToString(range.second.get<DateLUTImpl::Time>());
}
else if (isDateTime(column.type.get()) || isDateTime64(column.type.get()))
{
start_date_or_date_time = date_lut.timeToString(range.first.get<DateLUTImpl::Time>());
end_date_or_date_time = date_lut.timeToString(range.second.get<DateLUTImpl::Time>());
}
else [[unlikely]] return {};
if (comparator == "equals")
{
return makeASTFunction("and",
makeASTFunction("greaterOrEquals",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(start_date_or_date_time)
),
makeASTFunction("less",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(end_date_or_date_time)
)
);
}
else if (comparator == "notEquals")
{
return makeASTFunction("or",
makeASTFunction("less",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(start_date_or_date_time)
),
makeASTFunction("greaterOrEquals",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(end_date_or_date_time)
)
);
}
else if (comparator == "greater")
{
return makeASTFunction("greaterOrEquals",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(end_date_or_date_time)
);
}
else if (comparator == "lessOrEquals")
{
return makeASTFunction("less",
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(end_date_or_date_time)
);
}
else if (comparator == "less" || comparator == "greaterOrEquals")
{
return makeASTFunction(comparator,
std::make_shared<ASTIdentifier>(column_name),
std::make_shared<ASTLiteral>(start_date_or_date_time)
);
}
else [[unlikely]]
{
throw Exception(ErrorCodes::LOGICAL_ERROR,
"Expected equals, notEquals, less, lessOrEquals, greater, greaterOrEquals. Actual {}",
comparator);
}
}
void OptimizeDateOrDateTimeConverterWithPreimageMatcher::visit(const ASTFunction & function, ASTPtr & ast, const Data & data)
{
const static std::unordered_map<String, String> swap_relations = {
{"equals", "equals"},
{"notEquals", "notEquals"},
{"less", "greater"},
{"greater", "less"},
{"lessOrEquals", "greaterOrEquals"},
{"greaterOrEquals", "lessOrEquals"},
};
if (!swap_relations.contains(function.name))
return;
if (!function.arguments || function.arguments->children.size() != 2)
return;
size_t func_id = function.arguments->children.size();
for (size_t i = 0; i < function.arguments->children.size(); i++)
if (const auto * func = function.arguments->children[i]->as<ASTFunction>())
func_id = i;
if (func_id == function.arguments->children.size())
return;
size_t literal_id = 1 - func_id;
const auto * literal = function.arguments->children[literal_id]->as<ASTLiteral>();
if (!literal || literal->value.getType() != Field::Types::UInt64)
return;
String comparator = literal_id > func_id ? function.name : swap_relations.at(function.name);
const auto * ast_func = function.arguments->children[func_id]->as<ASTFunction>();
/// Currently we only handle single-argument functions.
if (!ast_func || !ast_func->arguments || ast_func->arguments->children.size() != 1)
return;
const auto * column_id = ast_func->arguments->children.at(0)->as<ASTIdentifier>();
if (!column_id)
return;
auto pos = IdentifierSemantic::getMembership(*column_id);
if (!pos)
pos = IdentifierSemantic::chooseTableColumnMatch(*column_id, data.tables, true);
if (!pos)
return;
if (*pos >= data.tables.size())
return;
auto data_type_and_name = data.tables[*pos].columns.tryGetByName(column_id->shortName());
if (!data_type_and_name)
return;
const auto column_type = data_type_and_name->type;
if (!column_type || (!isDateOrDate32(*column_type) && !isDateTime(*column_type) && !isDateTime64(*column_type)))
return;
const auto & converter = FunctionFactory::instance().tryGet(ast_func->name, data.context);
if (!converter)
return;
ColumnsWithTypeAndName args;
args.emplace_back(column_type, "tmp");
auto converter_base = converter->build(args);
if (!converter_base || !converter_base->hasInformationAboutPreimage())
return;
auto preimage_range = converter_base->getPreimage(*column_type, literal->value);
if (!preimage_range)
return;
const auto new_ast = generateOptimizedDateFilterAST(comparator, *data_type_and_name, *preimage_range);
if (!new_ast)
return;
ast = new_ast;
}
bool OptimizeDateOrDateTimeConverterWithPreimageMatcher::needChildVisit(ASTPtr & ast, ASTPtr & /*child*/)
{
const static std::unordered_set<String> relations = {
"equals",
"notEquals",
"less",
"greater",
"lessOrEquals",
"greaterOrEquals",
};
if (const auto * ast_function = ast->as<ASTFunction>())
{
return !relations.contains(ast_function->name);
}
return true;
}
}
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