Sorting related info. More...

#include <filesort.h>

Public Member Functions
	Filesort (THD thd, Mem_root_array< TABLE > tables, bool keep_buffers, ORDER *order, ha_rows limit_arg, bool remove_duplicates, bool force_sort_rowids, bool unwrap_rollup)

Addon_fields *	get_addon_fields (Addon_fields_status addon_fields_status, uint plength, uint *ppackable_length)
	Get descriptors of fields appended to sorted fields and calculate their total length. More...

uint	sort_order_length () const

bool	using_addon_fields ()
	Whether we are using addon fields (sort entire rows) or not (sort row IDs). More...

void	clear_addon_fields ()
	Reset the decision made in using_addon_fields(). More...

Public Attributes
THD *	m_thd

Mem_root_array< TABLE * >	tables
	The tables we are sorting. More...

const bool	keep_buffers
	If true, do not free the filesort buffers (use if you expect to sort many times, like in an uncacheable subquery). More...

ha_rows	limit
	Maximum number of rows to return. More...

st_sort_field *	sortorder
	ORDER BY list with some precalculated info for filesort. More...

bool	using_pq
	true means we are using Priority Queue for order by with limit. More...

bool	m_remove_duplicates

bool	m_force_sort_rowids

Sort_param	m_sort_param

Private Member Functions
uint	make_sortorder (ORDER *order, bool unwrap_rollup)

Private Attributes
uint	m_sort_order_length

Detailed Description

Sorting related info.

Constructor & Destructor Documentation

◆ Filesort()

Filesort::Filesort	(	THD *	thd,
		Mem_root_array< TABLE * >	tables,
		bool	keep_buffers,
		ORDER *	order,
		ha_rows	limit_arg,
		bool	remove_duplicates,
		bool	force_sort_rowids,
		bool	unwrap_rollup
	)

Member Function Documentation

◆ clear_addon_fields()

void Filesort::clear_addon_fields ( )

Reset the decision made in using_addon_fields().

Only used in exceptional circumstances (see NewWeedoutAccessPathForTables()).

◆ get_addon_fields()

Addon_fields * Filesort::get_addon_fields	(	Addon_fields_status *	addon_fields_status,
		uint *	plength,
		uint *	ppackable_length
	)

Get descriptors of fields appended to sorted fields and calculate their total length.

The function first finds out what fields are used in the result set. Then it calculates the length of the buffer to store the values of these fields together with the value of sort values. If there are no large blobs (which prevent addon fields), the function allocates memory for an array of descriptors containing layouts for the values of the non-sorted fields in the buffer and fills them.

Parameters

[out]	addon_fields_status	Reason for not using packed addon fields
[out]	plength	Total length of appended fields
[out]	ppackable_length	Total length of appended fields having a packable type

Note: The null bits for the appended values are supposed to be put together and stored into the buffer just ahead of the value of the first field.

Returns: Pointer to the layout descriptors for the appended fields, if any; NULL if we do not store field values with sort data.

◆ make_sortorder()

uint Filesort::make_sortorder	(	ORDER *	order,
		bool	unwrap_rollup
	)

private

◆ sort_order_length()

uint Filesort::sort_order_length ( ) const

inline

◆ using_addon_fields()

bool Filesort::using_addon_fields ( )

Whether we are using addon fields (sort entire rows) or not (sort row IDs).

Note that on the first call, this actually makes Sort_param compute the decision and cache it, so it cannot be called before the sort order is properly set up.

Member Data Documentation

◆ keep_buffers

const bool Filesort::keep_buffers

If true, do not free the filesort buffers (use if you expect to sort many times, like in an uncacheable subquery).

◆ limit

ha_rows Filesort::limit

Maximum number of rows to return.

◆ m_force_sort_rowids

bool Filesort::m_force_sort_rowids

◆ m_remove_duplicates

bool Filesort::m_remove_duplicates

◆ m_sort_order_length

uint Filesort::m_sort_order_length

private

◆ m_sort_param

Sort_param Filesort::m_sort_param

◆ m_thd

THD* Filesort::m_thd

◆ sortorder

st_sort_field* Filesort::sortorder

ORDER BY list with some precalculated info for filesort.

◆ tables

Mem_root_array<TABLE *> Filesort::tables

The tables we are sorting.

◆ using_pq

bool Filesort::using_pq

true means we are using Priority Queue for order by with limit.

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

sql/filesort.h
sql/filesort.cc

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes