The iterator actually doing the reads from the inner table during BKA. More...

#include <bka_iterator.h>

Inheritance diagram for MultiRangeRowIterator:

Public Member Functions
	MultiRangeRowIterator (THD thd, TABLE table, Index_lookup ref, int mrr_flags, JoinType join_type, const Prealloced_array< TABLE , 4 > &outer_input_tables, bool store_rowids, table_map tables_to_get_rowid_for)

void	set_rows (const hash_join_buffer::BufferRow begin, const hash_join_buffer::BufferRow end)
	Specify which outer rows to read inner rows for. More...

void	set_mrr_buffer (uchar *ptr, size_t size)
	Specify an unused chunk of memory MRR can use for the returned inner rows. More...

void	set_match_flag_buffer (uchar *ptr)
	Specify an unused chunk of memory that we can use to mark which inner rows have been read (by the parent BKA iterator) or not. More...

void	MarkLastRowAsRead ()
	Mark that the BKA iterator has seen the last row we returned from Read(). More...

bool	RowHasBeenRead (const hash_join_buffer::BufferRow *row) const
	Check whether the given row has been marked as read (using MarkLastRowAsRead()) or not. More...

bool	Init () override
	Do the actual multi-range read with the rows given by set_rows() and using the temporary buffer given in set_mrr_buffer(). More...

int	Read () override
	Read another inner row (if any) and load the appropriate outer row(s) into the associated table buffers. More...

Public Member Functions inherited from TableRowIterator
	TableRowIterator (THD thd, TABLE table)

void	UnlockRow () override
	The default implementation of unlock-row method of RowIterator, used in all access methods except EQRefIterator. More...

void	SetNullRowFlag (bool is_null_row) override
	Mark the current row buffer as containing a NULL row or not, so that if you read from it and the flag is true, you'll get only NULLs no matter what is actually in the buffer (typically some old leftover row). More...

void	StartPSIBatchMode () override
	Start performance schema batch mode, if supported (otherwise ignored). More...

void	EndPSIBatchModeIfStarted () override
	Ends performance schema batch mode, if started. More...

Public Member Functions inherited from RowIterator
	RowIterator (THD *thd)

virtual	~RowIterator ()=default

	RowIterator (const RowIterator &)=delete

	RowIterator (RowIterator &&)=default

virtual const IteratorProfiler *	GetProfiler () const
	Get profiling data for this iterator (for 'EXPLAIN ANALYZE'). More...

virtual void	SetOverrideProfiler ([[maybe_unused]] const IteratorProfiler *profiler)

virtual RowIterator *	real_iterator ()
	If this iterator is wrapping a different iterator (e.g. More...

virtual const RowIterator *	real_iterator () const

Private Member Functions
range_seq_t	MrrInitCallback (uint n_ranges, uint flags)

uint	MrrNextCallback (KEY_MULTI_RANGE *range)

bool	MrrSkipIndexTuple (char *range_info)

bool	MrrSkipRecord (char *range_info)

Static Private Member Functions
static range_seq_t	MrrInitCallbackThunk (void *init_params, uint n_ranges, uint flags)

static uint	MrrNextCallbackThunk (void init_params, KEY_MULTI_RANGE range)

static bool	MrrSkipRecordCallbackThunk (range_seq_t seq, char range_info, uchar )

Private Attributes
handler *const	m_file
	Handler for the table we are reading from. More...

Index_lookup *const	m_ref
	The index condition. More...

const int	m_mrr_flags
	Flags passed on to MRR. More...

const hash_join_buffer::BufferRow *	m_begin
	Current outer rows to read inner rows for. Set by set_rows(). More...

const hash_join_buffer::BufferRow *	m_end

const hash_join_buffer::BufferRow *	m_current_pos
	Which row we are at in the [m_begin, m_end) range. More...

const hash_join_buffer::BufferRow *	m_last_row_returned
	What row we last returned from Read() (used for MarkLastRowAsRead()). More...

HANDLER_BUFFER	m_mrr_buffer
	Temporary space for storing inner rows, used by MRR. More...

uchar *	m_match_flag_buffer = nullptr
	See set_match_flag_buffer(). More...

pack_rows::TableCollection	m_outer_input_tables
	Tables and columns needed for each outer row. More...

const JoinType	m_join_type
	The join type of the BKA join we are part of. More...

Additional Inherited Members
Protected Member Functions inherited from TableRowIterator
int	HandleError (int error)

void	PrintError (int error)

TABLE *	table () const

Protected Member Functions inherited from RowIterator
THD *	thd () const

Detailed Description

The iterator actually doing the reads from the inner table during BKA.

See file comment.

Constructor & Destructor Documentation

◆ MultiRangeRowIterator()

MultiRangeRowIterator::MultiRangeRowIterator	(	THD *	thd,
		TABLE *	table,
		Index_lookup *	ref,
		int	mrr_flags,
		JoinType	join_type,
		const Prealloced_array< TABLE *, 4 > &	outer_input_tables,
		bool	store_rowids,
		table_map	tables_to_get_rowid_for
	)

Parameters

thd	Thread handle.
table	The inner table to scan.
ref	The index condition we are looking up on.
mrr_flags	Flags passed on to MRR.
join_type	What kind of BKA join this MRR iterator is part of.
outer_input_tables	Which tables are on the left side of the BKA join (the MRR iterator is always alone on the right side). This is needed so that it can unpack the rows into the right tables, with the right format.
store_rowids	Whether we need to keep row IDs.
tables_to_get_rowid_for	Tables we need to call table->file->position() for; if a table is present in outer_input_tables but not this, some other iterator will make sure that table has the correct row ID already present after Read().

Member Function Documentation

◆ Init()

bool MultiRangeRowIterator::Init ( void )

overridevirtual

Do the actual multi-range read with the rows given by set_rows() and using the temporary buffer given in set_mrr_buffer().

We don't send a set of rows directly to MRR; instead, we give it a set of function pointers to iterate over the rows, and a pointer to ourselves. The handler will call our callbacks as follows:

MrrInitCallback at the start, to initialize iteration.
MrrNextCallback is called to yield ranges to scan, until it returns 1.

Implements RowIterator.

◆ MarkLastRowAsRead()

void MultiRangeRowIterator::MarkLastRowAsRead ( )

inline

Mark that the BKA iterator has seen the last row we returned from Read().

(It could have been discarded by a FilterIterator before it reached them.) Will be a no-op for inner joins; see set_match_flag_buffer()..

◆ MrrInitCallback()

range_seq_t MultiRangeRowIterator::MrrInitCallback	(	uint	n_ranges,
		uint	flags
	)

private

◆ MrrInitCallbackThunk()

static range_seq_t MultiRangeRowIterator::MrrInitCallbackThunk	(	void *	init_params,
		uint	n_ranges,
		uint	flags
	)

inlinestaticprivate

◆ MrrNextCallback()

uint MultiRangeRowIterator::MrrNextCallback ( KEY_MULTI_RANGE * range )

private

◆ MrrNextCallbackThunk()

static uint MultiRangeRowIterator::MrrNextCallbackThunk	(	void *	init_params,
		KEY_MULTI_RANGE *	range
	)

inlinestaticprivate

◆ MrrSkipIndexTuple()

bool MultiRangeRowIterator::MrrSkipIndexTuple ( char * range_info )

private

◆ MrrSkipRecord()

bool MultiRangeRowIterator::MrrSkipRecord ( char * range_info )

private

◆ MrrSkipRecordCallbackThunk()

static bool MultiRangeRowIterator::MrrSkipRecordCallbackThunk	(	range_seq_t	seq,
		char *	range_info,
		uchar *
	)

inlinestaticprivate

◆ Read()

int MultiRangeRowIterator::Read ( )

overridevirtual

Read another inner row (if any) and load the appropriate outer row(s) into the associated table buffers.

Implements RowIterator.

◆ RowHasBeenRead()

bool MultiRangeRowIterator::RowHasBeenRead ( const hash_join_buffer::BufferRow * row ) const

inline

Check whether the given row has been marked as read (using MarkLastRowAsRead()) or not.

Used internally when doing semijoins, and also by the BKAIterator when synthesizing NULL-complemented rows for outer joins or antijoins.

◆ set_match_flag_buffer()

void MultiRangeRowIterator::set_match_flag_buffer ( uchar * ptr )

inline

Specify an unused chunk of memory that we can use to mark which inner rows have been read (by the parent BKA iterator) or not.

This is used for outer joins to know which rows need NULL-complemented versions, and for semijoins and antijoins to avoid matching the same inner row more than once.

Must be called before Init() for semijoins, outer joins and antijoins, and never called otherwise. There must be room at least for one bit per row given in set_rows().

◆ set_mrr_buffer()

void MultiRangeRowIterator::set_mrr_buffer	(	uchar *	ptr,
		size_t	size
	)

inline

Specify an unused chunk of memory MRR can use for the returned inner rows.

Must be called before Init(), and must be at least big enough to hold one inner row.

◆ set_rows()

void MultiRangeRowIterator::set_rows	(	const hash_join_buffer::BufferRow *	begin,
		const hash_join_buffer::BufferRow *	end
	)

inline

Specify which outer rows to read inner rows for.

Must be called before Init(), and be valid until the last Read().

Member Data Documentation

◆ m_begin

const hash_join_buffer::BufferRow* MultiRangeRowIterator::m_begin

private

Current outer rows to read inner rows for. Set by set_rows().

◆ m_current_pos

const hash_join_buffer::BufferRow* MultiRangeRowIterator::m_current_pos

private

Which row we are at in the [m_begin, m_end) range.

Used during the MRR callbacks.

◆ m_end

const hash_join_buffer::BufferRow* MultiRangeRowIterator::m_end

private

◆ m_file

handler* const MultiRangeRowIterator::m_file

private

Handler for the table we are reading from.

◆ m_join_type

const JoinType MultiRangeRowIterator::m_join_type

private

The join type of the BKA join we are part of.

Same as m_join_type in the corresponding BKAIterator.

◆ m_last_row_returned

const hash_join_buffer::BufferRow* MultiRangeRowIterator::m_last_row_returned

private

What row we last returned from Read() (used for MarkLastRowAsRead()).

◆ m_match_flag_buffer

uchar* MultiRangeRowIterator::m_match_flag_buffer = nullptr

private

See set_match_flag_buffer().

◆ m_mrr_buffer

HANDLER_BUFFER MultiRangeRowIterator::m_mrr_buffer

private

Temporary space for storing inner rows, used by MRR.

Set by set_mrr_buffer().

◆ m_mrr_flags

const int MultiRangeRowIterator::m_mrr_flags

private

Flags passed on to MRR.

◆ m_outer_input_tables

pack_rows::TableCollection MultiRangeRowIterator::m_outer_input_tables

private

Tables and columns needed for each outer row.

Same as m_outer_input_tables in the corresponding BKAIterator.

◆ m_ref

Index_lookup* const MultiRangeRowIterator::m_ref

private

The index condition.

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

sql/iterators/bka_iterator.h
sql/iterators/bka_iterator.cc

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MultiRangeRowIterator()

Member Function Documentation

◆ Init()

◆ MarkLastRowAsRead()

◆ MrrInitCallback()

◆ MrrInitCallbackThunk()

◆ MrrNextCallback()

◆ MrrNextCallbackThunk()

◆ MrrSkipIndexTuple()

◆ MrrSkipRecord()

◆ MrrSkipRecordCallbackThunk()

◆ Read()

◆ RowHasBeenRead()

◆ set_match_flag_buffer()

◆ set_mrr_buffer()

◆ set_rows()

Member Data Documentation

◆ m_begin

◆ m_current_pos

◆ m_end

◆ m_file

◆ m_join_type

◆ m_last_row_returned

◆ m_match_flag_buffer

◆ m_mrr_buffer

◆ m_mrr_flags

◆ m_outer_input_tables

◆ m_ref