MySQL 9.1.0
Source Code Documentation
RefIterator< Reverse > Class Template Referencefinal

For each record on the left side of a join (given in Init()), returns one or more matching rows from the given table, i.e., WHERE column=<ref>. More...

#include <ref_row_iterators.h>

Inheritance diagram for RefIterator< Reverse >:
[legend]

Public Member Functions

 RefIterator (THD *thd, TABLE *table, Index_lookup *ref, bool use_order, double expected_rows, ha_rows *examined_rows)
 
 ~RefIterator () 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 IteratorProfilerGetProfiler () const
 Get profiling data for this iterator (for 'EXPLAIN ANALYZE'). More...
 
virtual void SetOverrideProfiler (const IteratorProfiler *profiler)
 
virtual RowIteratorreal_iterator ()
 If this iterator is wrapping a different iterator (e.g. More...
 
virtual const RowIteratorreal_iterator () const
 

Private Attributes

Index_lookup *const m_ref
 
const bool m_use_order
 
const double m_expected_rows
 
ha_rows *const m_examined_rows
 
bool m_first_record_since_init
 
bool m_is_mvi_unique_filter_enabled
 

Additional Inherited Members

- Protected Member Functions inherited from TableRowIterator
int HandleError (int error)
 
void PrintError (int error)
 
TABLEtable () const
 
- Protected Member Functions inherited from RowIterator
THDthd () const
 

Detailed Description

template<bool Reverse>
class RefIterator< Reverse >

For each record on the left side of a join (given in Init()), returns one or more matching rows from the given table, i.e., WHERE column=<ref>.

Constructor & Destructor Documentation

◆ RefIterator()

template<bool Reverse>
RefIterator< Reverse >::RefIterator ( THD thd,
TABLE table,
Index_lookup ref,
bool  use_order,
double  expected_rows,
ha_rows examined_rows 
)
inline

◆ ~RefIterator()

template<bool Reverse>
RefIterator< Reverse >::~RefIterator ( )
override

Member Function Documentation

◆ Init()

template<bool Reverse>
bool RefIterator< 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 RefIterator< 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
0OK
-1End of records
1Error

Implements RowIterator.

Member Data Documentation

◆ m_examined_rows

template<bool Reverse>
ha_rows* const RefIterator< Reverse >::m_examined_rows
private

◆ m_expected_rows

template<bool Reverse>
const double RefIterator< Reverse >::m_expected_rows
private

◆ m_first_record_since_init

template<bool Reverse>
bool RefIterator< Reverse >::m_first_record_since_init
private

◆ m_is_mvi_unique_filter_enabled

template<bool Reverse>
bool RefIterator< Reverse >::m_is_mvi_unique_filter_enabled
private

◆ m_ref

template<bool Reverse>
Index_lookup* const RefIterator< Reverse >::m_ref
private

◆ m_use_order

template<bool Reverse>
const bool RefIterator< Reverse >::m_use_order
private

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