Cost_model_server Class Reference

API for getting cost estimates for server operations that are not directly related to a table object. More...

#include <opt_costmodel.h>

Public Types
enum	enum_tmptable_type { MEMORY_TMPTABLE , DISK_TMPTABLE }
	Temporary table types that the cost model differentiate between. More...

Public Member Functions
	Cost_model_server ()
virtual	~Cost_model_server ()
	Destructor for Cost_model_server objects. More...
void	init (Optimizer optimizer)
	Initialize the cost model object for a query. More...
double	row_evaluate_cost (double rows) const
	Cost of processing a number of records and evaluating the query condition on the records. More...
double	key_compare_cost (double keys) const
	Cost of doing a number of key compare operations. More...
double	tmptable_create_cost (enum_tmptable_type tmptable_type) const
	Cost estimate for creating a temporary table. More...
double	tmptable_readwrite_cost (enum_tmptable_type tmptable_type, double write_rows, double read_rows) const
	Cost estimate for inserting and reading records from a temporary table. More...

Protected Member Functions
const Cost_model_constants *	get_cost_constants () const
	Return a pointer to the object containing the current cost constants. More...

Protected Attributes
const Server_cost_constants *	m_server_cost_constants
bool	m_initialized
	Used for detecting if this object is used without having been initialized. More...

Private Member Functions
double	memory_tmptable_create_cost () const
	Cost of creating a temporary table in the memory storage engine. More...
double	memory_tmptable_row_cost () const
	Cost of storing or retrieving a row using the memory storage engine. More...
double	disk_tmptable_create_cost () const
	Cost of creating a temporary table using a disk based storage engine. More...
double	disk_tmptable_row_cost () const
	Cost of storing or retrieving a row using a disk based storage engine. More...
double	tmptable_row_cost (enum_tmptable_type tmptable_type) const
	Cost estimate for a row operation (insert, read) on a temporary table. More...

Private Attributes
const Cost_model_constants *	m_cost_constants
	Cost constants to use in cost calculations. More...

Friends
class	Cost_model_table

Detailed Description

API for getting cost estimates for server operations that are not directly related to a table object.

Member Enumeration Documentation

enum_tmptable_type

enum Cost_model_server::enum_tmptable_type

Temporary table types that the cost model differentiate between.

Enumerator
MEMORY_TMPTABLE
DISK_TMPTABLE

Constructor & Destructor Documentation

Cost_model_server()

Cost_model_server::Cost_model_server ( )

inline

~Cost_model_server()

Cost_model_server::~Cost_model_server ( )

virtual

Destructor for Cost_model_server objects.

Note

This is declared virtual in order to make it easier to implement stubs for this class for use in unit tests.

Member Function Documentation

disk_tmptable_create_cost()

double Cost_model_server::disk_tmptable_create_cost ( ) const

inlineprivate

Cost of creating a temporary table using a disk based storage engine.

disk_tmptable_row_cost()

double Cost_model_server::disk_tmptable_row_cost ( ) const

inlineprivate

Cost of storing or retrieving a row using a disk based storage engine.

get_cost_constants()

const Cost_model_constants * Cost_model_server::get_cost_constants ( ) const

inlineprotected

Return a pointer to the object containing the current cost constants.

Returns

Cost constants

init()

void Cost_model_server::init

(

Optimizer

optimizer

)

Initialize the cost model object for a query.

This function must be called before calling any cost estimation functions for a query. It should also be called when starting optimization of a new query in case any cost estimate constants have changed.

Parameters

optimizer

The type of optimizer to initialize the cost model for.

key_compare_cost()

double Cost_model_server::key_compare_cost ( double  keys ) const

inline

Cost of doing a number of key compare operations.

Parameters

keys	number of key compare operations

Returns

Cost of comparing the keys

memory_tmptable_create_cost()

double Cost_model_server::memory_tmptable_create_cost ( ) const

inlineprivate

Cost of creating a temporary table in the memory storage engine.

memory_tmptable_row_cost()

double Cost_model_server::memory_tmptable_row_cost ( ) const

inlineprivate

Cost of storing or retrieving a row using the memory storage engine.

row_evaluate_cost()

double Cost_model_server::row_evaluate_cost ( double  rows ) const

inline

Cost of processing a number of records and evaluating the query condition on the records.

Parameters

rows	number of rows to evaluate

Returns

Cost of evaluating the records

tmptable_create_cost()

double Cost_model_server::tmptable_create_cost ( enum_tmptable_type  tmptable_type ) const

inline

Cost estimate for creating a temporary table.

Parameters

tmptable_type

storage type for the temporary table

Returns

Cost estimate

tmptable_readwrite_cost()

double Cost_model_server::tmptable_readwrite_cost ( enum_tmptable_type  tmptable_type, double  write_rows, double  read_rows  ) const

inline

Cost estimate for inserting and reading records from a temporary table.

Parameters

tmptable_type	storage type for the temporary table
write_rows	number of rows that will be written to table
read_rows	number of rows that will be read from table

Returns

The estimated cost

tmptable_row_cost()

double Cost_model_server::tmptable_row_cost ( enum_tmptable_type  tmptable_type ) const

inlineprivate

Cost estimate for a row operation (insert, read) on a temporary table.

Parameters

tmptable_type

storage type for the temporary table

Returns

The estimated cost

Friends And Related Function Documentation

Cost_model_table

friend class Cost_model_table

friend

Member Data Documentation

m_cost_constants

const Cost_model_constants* Cost_model_server::m_cost_constants

private

Cost constants to use in cost calculations.

m_initialized

bool Cost_model_server::m_initialized

protected

Used for detecting if this object is used without having been initialized.

m_server_cost_constants

const Server_cost_constants* Cost_model_server::m_server_cost_constants

protected

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

• sql/opt_costmodel.h
• sql/opt_costmodel.cc