IndexMergeIterator Class Reference

#include <index_merge.h>

Inheritance diagram for IndexMergeIterator:

Public Member Functions
	IndexMergeIterator (THD *thd, MEM_ROOT *mem_root, TABLE *table, unique_ptr_destroy_only< RowIterator > pk_quick_select, Mem_root_array< unique_ptr_destroy_only< RowIterator > > children)
	~IndexMergeIterator () override
bool	Init () override
	Initialize or reinitialize the iterator. More...
int	Read () override
	Read a single row. 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 Attributes
unique_ptr_destroy_only< Unique >	unique
unique_ptr_destroy_only< RowIterator >	read_record
unique_ptr_destroy_only< RowIterator >	pk_quick_select
Mem_root_array< unique_ptr_destroy_only< RowIterator > >	m_children
bool	doing_pk_scan
MEM_ROOT *	mem_root

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

Constructor & Destructor Documentation

IndexMergeIterator()

IndexMergeIterator::IndexMergeIterator	(	THD *	thd,
		MEM_ROOT *	mem_root,
		TABLE *	table,
		unique_ptr_destroy_only< RowIterator >	pk_quick_select,
		Mem_root_array< unique_ptr_destroy_only< RowIterator > >	children
	)

~IndexMergeIterator()

IndexMergeIterator::~IndexMergeIterator ( )

override

Member Function Documentation

Init()

bool IndexMergeIterator::Init ( )

overridevirtual

Initialize or reinitialize the iterator.

You must always call Init() before trying a Read() (but Init() does not imply Read()).

You can call Init() multiple times; subsequent calls will rewind the iterator (or reposition it, depending on whether the iterator takes in e.g. a Index_lookup) and allow you to read the records anew.

Implements RowIterator.

Read()

int IndexMergeIterator::Read ( )

overridevirtual

Read a single row.

The row data is not actually returned from the function; it is put in the table's (or tables', in case of a join) record buffer, ie., table->records[0].

Return values

0	OK
-1	End of records
1	Error

Implements RowIterator.

Member Data Documentation

doing_pk_scan

bool IndexMergeIterator::doing_pk_scan

private

m_children

Mem_root_array<unique_ptr_destroy_only<RowIterator> > IndexMergeIterator::m_children

private

mem_root

MEM_ROOT* IndexMergeIterator::mem_root

private

pk_quick_select

unique_ptr_destroy_only<RowIterator> IndexMergeIterator::pk_quick_select

private

read_record

unique_ptr_destroy_only<RowIterator> IndexMergeIterator::read_record

private

unique

unique_ptr_destroy_only<Unique> IndexMergeIterator::unique

private

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

• sql/range_optimizer/index_merge.h
• sql/range_optimizer/index_merge.cc