Cost_model_constants Class Reference

Set of all cost constants used by the server and all storage engines. More...

#include <opt_costconstants.h>

Public Member Functions
	Cost_model_constants ()
	Creates a set with cost constants using the default values defined in the source code. More...
virtual	~Cost_model_constants ()
	Destructor. More...
const Server_cost_constants *	get_server_cost_constants () const
	Get the cost constants that should be used for server operations. More...
const SE_cost_constants *	get_se_cost_constants (const TABLE *table) const
	Return the cost constants that should be used for a given table. More...
cost_constant_error	update_server_cost_constant (const LEX_CSTRING &name, double value)
	Update the value for one of the server cost constants. More...
cost_constant_error	update_engine_cost_constant (THD *thd, const LEX_CSTRING &se_name, uint storage_category, const LEX_CSTRING &name, double value)
	Update the value for one of the storage engine cost constants. More...

Protected Member Functions
void	inc_ref_count ()
	Increment the reference counter for this cost constant set. More...
unsigned int	dec_ref_count ()
	Decrement the reference counter for this cost constant set. More...

Private Member Functions
virtual uint	find_handler_slot_from_name (THD *thd, const LEX_CSTRING &name) const
	Utility function for finding the slot number for a storage engine based on the storage engine name. More...
cost_constant_error	update_engine_default_cost (const LEX_CSTRING &name, uint storage_category, double value)
	Update the default value for a storage engine cost constant. More...

Private Attributes
Server_cost_constants	m_server_constants
	Cost constants for server operations. More...
Prealloced_array< Cost_model_se_info, 15 >	m_engines
	Cost constants for storage engines 15 should be enough for most use cases, see PREALLOC_NUM_HA. More...
unsigned int	m_ref_counter
	Reference counter for this set of cost constants. More...

Friends
class	Cost_constant_cache

Detailed Description

Set of all cost constants used by the server and all storage engines.

Constructor & Destructor Documentation

Cost_model_constants()

Cost_model_constants::Cost_model_constants

(

)

Creates a set with cost constants using the default values defined in the source code.

Create default cost constants for each storage engine.

~Cost_model_constants()

Cost_model_constants::~Cost_model_constants ( )

virtual

Destructor.

Note

The only reason for making this virtual is to be able to make a sub-class for use in unit testing.

Member Function Documentation

dec_ref_count()

unsigned int Cost_model_constants::dec_ref_count ( )

inlineprotected

Decrement the reference counter for this cost constant set.

When the returned value is zero, there is nobody using this object and it can be deleted by the caller.

Returns

the updated reference count

find_handler_slot_from_name()

uint Cost_model_constants::find_handler_slot_from_name ( THD *  thd, const LEX_CSTRING &  name  ) const

privatevirtual

Utility function for finding the slot number for a storage engine based on the storage engine name.

The only reason for making this function virtual is to be able to override it in unit tests.

Parameters

thd	the THD
name	name of storage engine

Returns

slot number for the storage engine, HA_SLOT_UNDEF if there is no handler for this name

get_se_cost_constants()

const SE_cost_constants * Cost_model_constants::get_se_cost_constants

(

const TABLE *

table

)

const

Return the cost constants that should be used for a given table.

Parameters

table

the table to find cost constants for

Returns

the cost constants to use for the table

get_server_cost_constants()

const Server_cost_constants * Cost_model_constants::get_server_cost_constants ( ) const

inline

Get the cost constants that should be used for server operations.

Returns

the cost constants for the server

inc_ref_count()

void Cost_model_constants::inc_ref_count ( )

inlineprotected

Increment the reference counter for this cost constant set.

update_engine_cost_constant()

cost_constant_error Cost_model_constants::update_engine_cost_constant	(	THD *	thd,
		const LEX_CSTRING &	se_name,
		uint	storage_category,
		const LEX_CSTRING &	name,
		double	value
	)

Update the value for one of the storage engine cost constants.

Parameters

thd	the THD
se_name	name of storage engine
storage_category	storage device type
name	name of cost constant
value	new value

Returns

Status for updating the cost constant

update_engine_default_cost()

cost_constant_error Cost_model_constants::update_engine_default_cost ( const LEX_CSTRING &  name, uint  storage_category, double  value  )

private

Update the default value for a storage engine cost constant.

Parameters

name	name of cost constant
storage_category	storage device type
value	new value

Returns

Status for updating the cost constant

update_server_cost_constant()

cost_constant_error Cost_model_constants::update_server_cost_constant	(	const LEX_CSTRING &	name,
		double	value
	)

Update the value for one of the server cost constants.

Parameters

name	name of the cost constant
value	new value

Returns

Status for updating the cost constant

Friends And Related Function Documentation

Cost_constant_cache

friend class Cost_constant_cache

friend

Member Data Documentation

m_engines

Prealloced_array<Cost_model_se_info, 15> Cost_model_constants::m_engines

private

Cost constants for storage engines 15 should be enough for most use cases, see PREALLOC_NUM_HA.

m_ref_counter

unsigned int Cost_model_constants::m_ref_counter

private

Reference counter for this set of cost constants.

m_server_constants

Server_cost_constants Cost_model_constants::m_server_constants

private

Cost constants for server operations.

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

• sql/opt_costconstants.h
• sql/opt_costconstants.cc