IndexDistanceScanIterator Class Reference

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

#include <basic_row_iterators.h>

Inheritance diagram for IndexDistanceScanIterator:

Public Member Functions
	IndexDistanceScanIterator (THD *thd, TABLE *table, int idx, QUICK_RANGE *query_mbr, double expected_rows, ha_rows *examined_rows)
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 (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
QUICK_RANGE *	m_query_mbr
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

Perform a distance index scan along an index.

For now it is just like the IndexScanIterator, waiting for innodb implementation of distance index scan functions

Constructor & Destructor Documentation

IndexDistanceScanIterator()

IndexDistanceScanIterator::IndexDistanceScanIterator	(	THD *	thd,
		TABLE *	table,
		int	idx,
		QUICK_RANGE *	query_mbr,
		double	expected_rows,
		ha_rows *	examined_rows
	)

Member Function Documentation

Init()

bool IndexDistanceScanIterator::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 IndexDistanceScanIterator::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

ha_rows* const IndexDistanceScanIterator::m_examined_rows

private

m_expected_rows

const double IndexDistanceScanIterator::m_expected_rows

private

m_first

bool IndexDistanceScanIterator::m_first = true

private

m_idx

const int IndexDistanceScanIterator::m_idx

private

m_query_mbr

QUICK_RANGE* IndexDistanceScanIterator::m_query_mbr

private

m_record

uchar* const IndexDistanceScanIterator::m_record

private

---

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

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