The class hold dynamic table statistics for a table. More...

#include <table_stats.h>

Public Member Functions
	Table_statistics ()

bool	is_stat_cached_in_mem (const String &db_name, const String &table_name, const char *partition_name)
	Check if the stats are cached for given db.table_name. More...

bool	is_stat_cached_in_mem (const String &db_name, const String &table_name)

void	cache_stats_in_mem (const String &db_name, const String &table_name, const char partition_name, handler file)
	Store the statistics form the given handler. More...

void	cache_stats_in_mem (const String &db_name, const String &table_name, handler *file)

void	cache_stats_in_mem (const String &db_name, const String &table_name, const char *partition_name, ha_statistics &stats)
	Store the statistics. More...

void	cache_stats_in_mem (const String &db_name, const String &table_name, ha_statistics &stats)

ulonglong	read_stat (THD thd, const String &schema_name_ptr, const String &table_name_ptr, const String &index_name_ptr, const char partition_name, const String &column_name_ptr, uint index_ordinal_position, uint column_ordinal_position, const String &engine_name_ptr, dd::Object_id se_private_id, const char ts_se_private_data, const char tbl_se_private_data, const ulonglong &table_stat_data, const ulonglong &cached_time, enum_table_stats_type stype)
	Read dynamic table/index statistics from SE by opening the user table provided OR by reading cached statistics from Query_block. More...

ulonglong	read_stat (THD thd, const String &schema_name_ptr, const String &table_name_ptr, const String &engine_name_ptr, const char partition_name, dd::Object_id se_private_id, const char ts_se_private_data, const char tbl_se_private_data, const ulonglong &table_stat_data, const ulonglong &cached_time, enum_table_stats_type stype)

void	invalidate_cache (void)

String_type	error ()

void	store_error_message (const String &db_name, const String &table_name, const char *partition_name, const String_type &error_msg)
	Set error string for the given key. More...

bool	check_error_for_key (const String &db_name, const String &table_name)
	Check if we have seen a error. More...

bool	is_reading_stats_by_open () const
	Check if open table in progress. More...

bool	is_valid () const
	Predicate for determinig if cache is valid. More...

Public Attributes
ha_statistics	m_stats

Private Member Functions
ulonglong	read_stat_from_SE (THD thd, const String &schema_name_ptr, const String &table_name_ptr, const String &index_name_ptr, const String &column_name_ptr, uint index_ordinal_position, uint column_ordinal_position, dd::Object_id se_private_id, const char ts_se_private_data, const char tbl_se_private_data, enum_table_stats_type stype, handlerton hton)
	Read dynamic table/index statistics from SE API's OR by reading cached statistics from Query_block. More...

ulonglong	read_stat_by_open_table (THD thd, const String &schema_name_ptr, const String &table_name_ptr, const String &index_name_ptr, const char partition_name, const String &column_name_ptr, uint column_ordinal_position, enum_table_stats_type stype)
	Read dynamic table/index statistics by opening the table OR by reading cached statistics from Query_block. More...

void	set_stat_cached (const String &db_name, const String &table_name, const char *partition_name)
	Mark the cache as valid for a given table. More...

void	set_stat_cached (const String &db_name, const String &table_name)

String_type	form_key (const String &db_name, const String &table_name, const char *partition_name)
	Build a key representing the table for which stats are cached. More...

ulonglong	get_stat (ha_statistics &stat, enum_table_stats_type stype)
	Return statistics of the a given type. More...

ulonglong	get_stat (enum_table_stats_type stype)

void	set_checksum (ulonglong &&checksum)
	Set checksum. More...

ulonglong	get_checksum () const
	Get checksum. More...

void	set_read_stats_by_open (bool status)
	Set open table in progress. More...

Private Attributes
String_type	m_key

String_type	m_error

ulonglong	m_checksum

bool	m_read_stats_by_open

Detailed Description

The class hold dynamic table statistics for a table.

This cache is used by internal UDF's defined for the purpose of INFORMATION_SCHEMA queries which retrieve dynamic table statistics. The class caches statistics for just one table.

Overall aim of introducing this cache is to avoid making multiple calls to same SE API to retrieve the statistics.

Constructor & Destructor Documentation

◆ Table_statistics()

dd::info_schema::Table_statistics::Table_statistics ( )

inline

Member Function Documentation

◆ cache_stats_in_mem() [1/4]

void dd::info_schema::Table_statistics::cache_stats_in_mem	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name,
		ha_statistics &	stats
	)

inline

Store the statistics.

Parameters

db_name	- Schema name.
table_name	- Table name.
partition_name	- Partition name.
stats	- ha_statistics of the table.

◆ cache_stats_in_mem() [2/4]

void dd::info_schema::Table_statistics::cache_stats_in_mem	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name,
		handler *	file
	)

inline

Store the statistics form the given handler.

Parameters

db_name	- Schema name.
table_name	- Table name.
partition_name	- Partition name.
file	- Handler object for the table.

◆ cache_stats_in_mem() [3/4]

void dd::info_schema::Table_statistics::cache_stats_in_mem	(	const String &	db_name,
		const String &	table_name,
		ha_statistics &	stats
	)

inline

◆ cache_stats_in_mem() [4/4]

void dd::info_schema::Table_statistics::cache_stats_in_mem	(	const String &	db_name,
		const String &	table_name,
		handler *	file
	)

inline

◆ check_error_for_key()

bool dd::info_schema::Table_statistics::check_error_for_key	(	const String &	db_name,
		const String &	table_name
	)

inline

Check if we have seen a error.

Parameters

db_name	Database name.
table_name	Table name.

Returns: true if there is error reported. false if not.

◆ error()

String_type dd::info_schema::Table_statistics::error ( )

inline

◆ form_key()

String_type dd::info_schema::Table_statistics::form_key	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name
	)

inlineprivate

Build a key representing the table for which stats are cached.

Parameters

db_name	- Database name.
table_name	- Table name.
partition_name	- Partition name.

Returns: String_type representing the key.

◆ get_checksum()

ulonglong dd::info_schema::Table_statistics::get_checksum ( ) const

inlineprivate

Get checksum.

◆ get_stat() [1/2]

ulonglong dd::info_schema::Table_statistics::get_stat ( enum_table_stats_type stype )

inlineprivate

◆ get_stat() [2/2]

ulonglong dd::info_schema::Table_statistics::get_stat	(	ha_statistics &	stat,
		enum_table_stats_type	stype
	)

private

Return statistics of the a given type.

Parameters

stat	ha_statistics for the current cached table.
stype	Type of statistics requested.

Returns: ulonglong statistics value.

◆ invalidate_cache()

void dd::info_schema::Table_statistics::invalidate_cache ( void )

inline

◆ is_reading_stats_by_open()

bool dd::info_schema::Table_statistics::is_reading_stats_by_open ( ) const

inline

Check if open table in progress.

◆ is_stat_cached_in_mem() [1/2]

bool dd::info_schema::Table_statistics::is_stat_cached_in_mem	(	const String &	db_name,
		const String &	table_name
	)

inline

◆ is_stat_cached_in_mem() [2/2]

bool dd::info_schema::Table_statistics::is_stat_cached_in_mem	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name
	)

inline

Check if the stats are cached for given db.table_name.

Parameters

db_name	- Schema name.
table_name	- Table name.
partition_name	- Partition name.

Returns: true if stats are cached, else false.

◆ is_valid()

bool dd::info_schema::Table_statistics::is_valid ( void ) const

inline

Predicate for determinig if cache is valid.

◆ read_stat() [1/2]

ulonglong dd::info_schema::Table_statistics::read_stat	(	THD *	thd,
		const String &	schema_name_ptr,
		const String &	table_name_ptr,
		const String &	engine_name_ptr,
		const char *	partition_name,
		dd::Object_id	se_private_id,
		const char *	ts_se_private_data,
		const char *	tbl_se_private_data,
		const ulonglong &	table_stat_data,
		const ulonglong &	cached_time,
		enum_table_stats_type	stype
	)

inline

◆ read_stat() [2/2]

ulonglong dd::info_schema::Table_statistics::read_stat	(	THD *	thd,
		const String &	schema_name_ptr,
		const String &	table_name_ptr,
		const String &	index_name_ptr,
		const char *	partition_name,
		const String &	column_name_ptr,
		uint	index_ordinal_position,
		uint	column_ordinal_position,
		const String &	engine_name_ptr,
		dd::Object_id	se_private_id,
		const char *	ts_se_private_data,
		const char *	tbl_se_private_data,
		const ulonglong &	table_stat_data,
		const ulonglong &	cached_time,
		enum_table_stats_type	stype
	)

Read dynamic table/index statistics from SE by opening the user table provided OR by reading cached statistics from Query_block.

Parameters

thd	- Current thread.
schema_name_ptr	- Schema name of table.
table_name_ptr	- Table name of which we need stats.
index_name_ptr	- Index name of which we need stats.
partition_name	- Partition name.
column_name_ptr	- Column name for index.
index_ordinal_position	- Ordinal position of index in table.
column_ordinal_position	- Ordinal position of column in table.
engine_name_ptr	- Engine of the table.
se_private_id	- se_private_id of the table.
ts_se_private_data	- Tablespace SE private data.
tbl_se_private_data	- Table SE private data.
table_stat_data	- Cached data from mysql.table_stats / mysql.index_stats table
cached_time	- Timestamp value when data was cached.
stype	- Enum specifying the stat we are interested to read.

Returns: ulonglong representing value for the status being read.

◆ read_stat_by_open_table()

ulonglong dd::info_schema::Table_statistics::read_stat_by_open_table	(	THD *	thd,
		const String &	schema_name_ptr,
		const String &	table_name_ptr,
		const String &	index_name_ptr,
		const char *	partition_name,
		const String &	column_name_ptr,
		uint	column_ordinal_position,
		enum_table_stats_type	stype
	)

private

Read dynamic table/index statistics by opening the table OR by reading cached statistics from Query_block.

Parameters

thd	- Current thread.
schema_name_ptr	- Schema name of table.
table_name_ptr	- Table name of which we need stats.
index_name_ptr	- Index name of which we need stats.
column_name_ptr	- Column name for index.
column_ordinal_position	- Ordinal position of column in table.
partition_name	- Partition name.
stype	- Enum specifying the stat we are interested to read.

Returns: ulonglong representing value for the status being read.

◆ read_stat_from_SE()

ulonglong dd::info_schema::Table_statistics::read_stat_from_SE	(	THD *	thd,
		const String &	schema_name_ptr,
		const String &	table_name_ptr,
		const String &	index_name_ptr,
		const String &	column_name_ptr,
		uint	index_ordinal_position,
		uint	column_ordinal_position,
		dd::Object_id	se_private_id,
		const char *	ts_se_private_data,
		const char *	tbl_se_private_data,
		enum_table_stats_type	stype,
		handlerton *	hton
	)

private

Read dynamic table/index statistics from SE API's OR by reading cached statistics from Query_block.

Parameters

thd	- Current thread.
schema_name_ptr	- Schema name of table.
table_name_ptr	- Table name of which we need stats.
index_name_ptr	- Index name of which we need stats.
column_name_ptr	- Column name for index.
index_ordinal_position	- Ordinal position of index in table.
column_ordinal_position	- Ordinal position of column in table.
se_private_id	- se_private_id of the table.
ts_se_private_data	- Tablespace SE private data.
tbl_se_private_data	- Table SE private data.
stype	- Enum specifying the stat we are interested to read.
hton	- Handle to SE for the given table.

Returns: ulonglong representing value for the status being read.

◆ set_checksum()

void dd::info_schema::Table_statistics::set_checksum ( ulonglong && checksum )

inlineprivate

Set checksum.

◆ set_read_stats_by_open()

void dd::info_schema::Table_statistics::set_read_stats_by_open ( bool status )

inlineprivate

Set open table in progress.

◆ set_stat_cached() [1/2]

void dd::info_schema::Table_statistics::set_stat_cached	(	const String &	db_name,
		const String &	table_name
	)

inlineprivate

◆ set_stat_cached() [2/2]

void dd::info_schema::Table_statistics::set_stat_cached	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name
	)

inlineprivate

Mark the cache as valid for a given table.

This creates a key for the cache element. We store just a single table statistics in this cache.

Parameters

db_name	- Database name.
table_name	- Table name.
partition_name	- Partition name.

◆ store_error_message()

void dd::info_schema::Table_statistics::store_error_message	(	const String &	db_name,
		const String &	table_name,
		const char *	partition_name,
		const String_type &	error_msg
	)

inline

Set error string for the given key.

The combination of (db, table and partition name) forms the key.

Parameters

db_name	- Schema name.
table_name	- Table name.
partition_name	- Partition name.
error_msg	- Error message.

Note: We store the error message so that the error message is shown in I_S.TABLES.COMMENT field. Apart from storing the error message, the below function resets the statistics, this will make sure,

We do not invoke open_tables_for_query() again for other dynamic columns that are fetch from the current row being processed.
We will not see junk values for statistics in results.

Member Data Documentation

◆ m_checksum

ulonglong dd::info_schema::Table_statistics::m_checksum

private

◆ m_error

String_type dd::info_schema::Table_statistics::m_error

private

◆ m_key

String_type dd::info_schema::Table_statistics::m_key

private

◆ m_read_stats_by_open

bool dd::info_schema::Table_statistics::m_read_stats_by_open

private

◆ m_stats

ha_statistics dd::info_schema::Table_statistics::m_stats

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

sql/dd/info_schema/table_stats.h
sql/dd/info_schema/table_stats.cc

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Table_statistics()

Member Function Documentation

◆ cache_stats_in_mem() [1/4]

◆ cache_stats_in_mem() [2/4]

◆ cache_stats_in_mem() [3/4]

◆ cache_stats_in_mem() [4/4]

◆ check_error_for_key()

◆ error()

◆ form_key()

◆ get_checksum()

◆ get_stat() [1/2]

◆ get_stat() [2/2]

◆ invalidate_cache()

◆ is_reading_stats_by_open()

◆ is_stat_cached_in_mem() [1/2]

◆ is_stat_cached_in_mem() [2/2]

◆ is_valid()

◆ read_stat() [1/2]

◆ read_stat() [2/2]

◆ read_stat_by_open_table()

◆ read_stat_from_SE()

◆ set_checksum()

◆ set_read_stats_by_open()

◆ set_stat_cached() [1/2]

◆ set_stat_cached() [2/2]

◆ store_error_message()

Member Data Documentation

◆ m_checksum

◆ m_error

◆ m_key

◆ m_read_stats_by_open

◆ m_stats