Code used for background table and index stats gathering. More...

#include "sql_thd_internal_api.h"
#include <stddef.h>
#include <sys/types.h>
#include <vector>
#include "dict0dd.h"
#include "dict0dict.h"
#include "dict0stats.h"
#include "dict0stats_bg.h"
#include "os0thread-create.h"
#include "row0mysql.h"
#include "sql/histograms/histogram.h"
#include "srv0start.h"
#include "ut0new.h"

Typedefs
typedef ut::allocator< table_id_t >	recalc_pool_allocator_t
	Allocator type, used by std::vector. More...

typedef std::vector< table_id_t, recalc_pool_allocator_t >	recalc_pool_t
	The multitude of tables whose stats are to be automatically recalculated - an STL vector. More...

typedef recalc_pool_t::iterator	recalc_pool_iterator_t
	Iterator type for iterating over the elements of objects of type recalc_pool_t. More...

Functions
static bool	SHUTTING_DOWN ()

static void	dict_stats_recalc_pool_init ()
	Initialize the recalc pool, called once during thread initialization. More...

static void	dict_stats_recalc_pool_deinit ()
	Free the resources occupied by the recalc pool, called once during thread de-initialization. More...

void	dict_stats_recalc_pool_add (const dict_table_t *table)
	Add a table to the recalc pool, which is processed by the background stats gathering thread. More...

static bool	dict_stats_recalc_pool_get (table_id_t *id)
	Get a table from the auto recalc pool. More...

void	dict_stats_recalc_pool_del (const dict_table_t *table)
	Delete a given table from the auto recalc pool. More...

void	dict_stats_wait_bg_to_stop_using_table (dict_table_t table, trx_t trx)
	Wait until background stats thread has stopped using the specified table. More...

void	dict_stats_thread_init ()
	Initialize global variables needed for the operation of dict_stats_thread() Must be called before dict_stats_thread() is started. More...

void	dict_stats_thread_deinit ()
	Free resources allocated by dict_stats_thread_init(), must be called after dict_stats_thread() has exited. More...

static void	dict_stats_process_entry_from_recalc_pool (THD *thd)
	Get the first table that has been added for auto recalc and eventually update its stats. More...

void	dict_stats_disabled_debug_update (THD , SYS_VAR , void , const void save)
	Disables dict stats thread. More...

void	dict_stats_thread ()
	This is the thread for background stats gathering. More...

void	dict_stats_shutdown ()
	Shutdown the dict stats thread. More...

Variables
constexpr std::chrono::seconds	MIN_RECALC_INTERVAL {10}
	Minimum time interval between stats recalc for a given table. More...

os_event_t	dict_stats_event = nullptr
	Event to wake up the stats thread. More...

bool	innodb_dict_stats_disabled_debug
	Used by SET GLOBAL innodb_dict_stats_disabled_debug = 1;. More...

static os_event_t	dict_stats_disabled_event

static ib_mutex_t	recalc_pool_mutex
	This mutex protects the "recalc_pool" variable. More...

static const ulint	RECALC_POOL_INITIAL_SLOTS = 128
	The number of tables that can be added to "recalc_pool" before it is enlarged. More...

static recalc_pool_t *	recalc_pool
	Pool where we store information on which tables are to be processed by background statistics gathering. More...

Detailed Description

Code used for background table and index stats gathering.

Created Apr 25, 2012 Vasil Dimov

Typedef Documentation

◆ recalc_pool_allocator_t

typedef ut::allocator<table_id_t> recalc_pool_allocator_t

Allocator type, used by std::vector.

◆ recalc_pool_iterator_t

typedef recalc_pool_t::iterator recalc_pool_iterator_t

Iterator type for iterating over the elements of objects of type recalc_pool_t.

◆ recalc_pool_t

typedef std::vector<table_id_t, recalc_pool_allocator_t> recalc_pool_t

The multitude of tables whose stats are to be automatically recalculated - an STL vector.

Function Documentation

◆ dict_stats_disabled_debug_update()

void dict_stats_disabled_debug_update	(	THD *	thd,
		SYS_VAR *	var,
		void *	var_ptr,
		const void *	save
	)

Disables dict stats thread.

It's used by: SET GLOBAL innodb_dict_stats_disabled_debug = 1 (0).

Parameters

[in]	thd	thread handle
[in]	var	pointer to system variable
[out]	var_ptr	where the formal string goes
[in]	save	immediate result from check function

◆ dict_stats_process_entry_from_recalc_pool()

static void dict_stats_process_entry_from_recalc_pool ( THD * thd )

static

Get the first table that has been added for auto recalc and eventually update its stats.

Parameters

[in,out] thd current thread

◆ dict_stats_recalc_pool_add()

void dict_stats_recalc_pool_add ( const dict_table_t * table )

Add a table to the recalc pool, which is processed by the background stats gathering thread.

Only the table id is added to the list, so the table can be closed after being enqueued and it will be opened when needed. If the table does not exist later (has been DROPped), then it will be removed from the pool and skipped.

Parameters

table in: table to add

◆ dict_stats_recalc_pool_deinit()

static void dict_stats_recalc_pool_deinit ( )

static

Free the resources occupied by the recalc pool, called once during thread de-initialization.

◆ dict_stats_recalc_pool_del()

void dict_stats_recalc_pool_del ( const dict_table_t * table )

Delete a given table from the auto recalc pool.

dict_stats_recalc_pool_del()

Parameters

table in: table to remove

◆ dict_stats_recalc_pool_get()

static bool dict_stats_recalc_pool_get ( table_id_t * id )

static

Get a table from the auto recalc pool.

The returned table id is removed from the pool.

Returns: true if the pool was non-empty and "id" was set, false otherwise

Parameters

id	out: table id, or unmodified if list is empty

◆ dict_stats_recalc_pool_init()

static void dict_stats_recalc_pool_init ( )

static

Initialize the recalc pool, called once during thread initialization.

◆ dict_stats_shutdown()

void dict_stats_shutdown ( )

Shutdown the dict stats thread.

◆ dict_stats_thread()

void dict_stats_thread ( )

This is the thread for background stats gathering.

It pops tables, from the auto recalc list and proceeds them, eventually recalculating their statistics.

◆ dict_stats_thread_deinit()

void dict_stats_thread_deinit ( )

Free resources allocated by dict_stats_thread_init(), must be called after dict_stats_thread() has exited.

◆ dict_stats_thread_init()

void dict_stats_thread_init ( )

Initialize global variables needed for the operation of dict_stats_thread() Must be called before dict_stats_thread() is started.

Initialize global variables needed for the operation of dict_stats_thread().

◆ dict_stats_wait_bg_to_stop_using_table()

void dict_stats_wait_bg_to_stop_using_table	(	dict_table_t *	table,
		trx_t *	trx
	)

Wait until background stats thread has stopped using the specified table.

The caller must have locked the data dictionary using row_mysql_lock_data_dictionary() and this function may unlock it temporarily and restore the lock before it exits. The background stats thread is guaranteed not to start using the specified table after this function returns and before the caller unlocks the data dictionary because it sets the BG_STAT_IN_PROGRESS bit in table->stats_bg_flag under dict_sys->mutex.

Parameters

table	in/out: table
trx	in/out: transaction to use for unlocking/locking the data dict

◆ SHUTTING_DOWN()

static bool SHUTTING_DOWN ( )

inlinestatic

Variable Documentation

◆ dict_stats_disabled_event

os_event_t dict_stats_disabled_event

static

◆ dict_stats_event

os_event_t dict_stats_event = nullptr

Event to wake up the stats thread.

◆ innodb_dict_stats_disabled_debug

bool innodb_dict_stats_disabled_debug

Used by SET GLOBAL innodb_dict_stats_disabled_debug = 1;.

Value of MySQL global used to disable dict_stats thread.

◆ MIN_RECALC_INTERVAL

constexpr std::chrono::seconds MIN_RECALC_INTERVAL {10}

constexpr

Minimum time interval between stats recalc for a given table.

◆ recalc_pool

recalc_pool_t* recalc_pool

static

Pool where we store information on which tables are to be processed by background statistics gathering.

◆ RECALC_POOL_INITIAL_SLOTS

const ulint RECALC_POOL_INITIAL_SLOTS = 128

static

The number of tables that can be added to "recalc_pool" before it is enlarged.

◆ recalc_pool_mutex

ib_mutex_t recalc_pool_mutex

static

This mutex protects the "recalc_pool" variable.

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ recalc_pool_allocator_t

◆ recalc_pool_iterator_t

◆ recalc_pool_t

Function Documentation

◆ dict_stats_disabled_debug_update()

◆ dict_stats_process_entry_from_recalc_pool()

◆ dict_stats_recalc_pool_add()

◆ dict_stats_recalc_pool_deinit()

◆ dict_stats_recalc_pool_del()

◆ dict_stats_recalc_pool_get()

◆ dict_stats_recalc_pool_init()

◆ dict_stats_shutdown()

◆ dict_stats_thread()

◆ dict_stats_thread_deinit()

◆ dict_stats_thread_init()

◆ dict_stats_wait_bg_to_stop_using_table()

◆ SHUTTING_DOWN()

Variable Documentation

◆ dict_stats_disabled_event

◆ dict_stats_event

◆ innodb_dict_stats_disabled_debug

◆ MIN_RECALC_INTERVAL

◆ recalc_pool

◆ RECALC_POOL_INITIAL_SLOTS

◆ recalc_pool_mutex