IndexScanIterator< Reverse > Class Template Reference

Perform a full index scan along an index. More...

#include <basic_row_iterators.h>

Inheritance diagram for IndexScanIterator< Reverse >:

Public Member Functions
	IndexScanIterator (THD *thd, TABLE *table, int idx, bool use_order, double expected_rows, ha_rows *examined_rows)
	~IndexScanIterator () 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
uchar *const	m_record
const int	m_idx
const bool	m_use_order
const double	m_expected_rows
ha_rows *const	m_examined_rows
bool	m_first = true

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

template<bool Reverse>
class IndexScanIterator< Reverse >

Perform a full index scan along an index.

Constructor & Destructor Documentation

IndexScanIterator()

template<bool Reverse>

IndexScanIterator< Reverse >::IndexScanIterator	(	THD *	thd,
		TABLE *	table,
		int	idx,
		bool	use_order,
		double	expected_rows,
		ha_rows *	examined_rows
	)

~IndexScanIterator()

template<bool Reverse>

IndexScanIterator< Reverse >::~IndexScanIterator

override

Member Function Documentation

Init()

template<bool Reverse>

bool IndexScanIterator< Reverse >::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()

template<bool Reverse>

int IndexScanIterator< Reverse >::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

m_examined_rows

template<bool Reverse>

ha_rows* const IndexScanIterator< Reverse >::m_examined_rows

private

m_expected_rows

template<bool Reverse>

const double IndexScanIterator< Reverse >::m_expected_rows

private

m_first

template<bool Reverse>

bool IndexScanIterator< Reverse >::m_first = true

private

m_idx

template<bool Reverse>

const int IndexScanIterator< Reverse >::m_idx

private

m_record

template<bool Reverse>

uchar* const IndexScanIterator< Reverse >::m_record

private

m_use_order

template<bool Reverse>

const bool IndexScanIterator< Reverse >::m_use_order

private

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

• sql/iterators/basic_row_iterators.h
• sql/iterators/basic_row_iterators.cc