Group类 参考

A class representing a group within cascade optimizer. 更多...

#include <group.h>

Public 成员函数
	Group (int id, GroupExpr *expr, Memo *memo)
	Constructor for the Group class. A Group tracks both logical and physical M_EXPRs. 更多...
void	add_expr (GroupExpr *expr)
	Adds an expression to the group. 更多...
bool	set_expr_cost (GroupExpr *expr, double cost)
	Sets the cost of a given expression in the group. 更多...
GroupExpr *	get_winner ()
const std::vector< GroupExpr * > &	get_logical_expressions () const
	Gets the logical expressions in the group.
const std::vector< GroupExpr * > &	get_physical_expressions () const
	Gets the physical expressions in the group.
double	get_cost_lb ()
	Gets the cost lower bound. 更多...
void	set_explored ()
	Marks the group as explored.
bool	has_explored ()
	Checks if the group has been explored.
int	get_id () const
GroupExpr *	get_logical_expression ()
LogicalProperty *	get_logical_prop ()
	dump the group info, for debug
void	dump () const

Private 属性
int	id_
std::tuple< double, GroupExpr * >	winner_
bool	has_explored_
std::vector< GroupExpr * >	logical_expressions_
std::vector< GroupExpr * >	physical_expressions_
unique_ptr< LogicalProperty >	logical_prop_ = nullptr

详细描述

A class representing a group within cascade optimizer.

This class manages a group of expressions and their associated costs, and keeps track of whether the group has been explored.

构造及析构函数说明

Group()

Group::Group	(	int	id,
		GroupExpr *	expr,
		Memo *	memo
	)

Constructor for the Group class. A Group tracks both logical and physical M_EXPRs.

参数

id	The unique identifier for the group.

成员函数说明

add_expr()

void Group::add_expr

(

GroupExpr *

expr

)

Adds an expression to the group.

参数

expr	The expression to add.

get_cost_lb()

double Group::get_cost_lb ( )

inline

Gets the cost lower bound.

注解

This function is a work in progress (WIP).

get_winner()

GroupExpr * Group::get_winner

(

)

返回

The expression with the lowest cost.

set_expr_cost()

bool Group::set_expr_cost	(	GroupExpr *	expr,
		double	cost
	)

Sets the cost of a given expression in the group.

参数

expr	The expression for which to set the cost.
cost	The cost associated with the expression.

返回

True if the cost was successfully set, false if the expression is not setted.

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该类的文档由以下文件生成:

• src/observer/sql/optimizer/cascade/group.h
• src/observer/sql/optimizer/cascade/group.cpp