MySQL 8.4.0
Source Code Documentation
DynamicRangeIterator Class Referencefinal

#include <ref_row_iterators.h>

Inheritance diagram for DynamicRangeIterator:

Public Member Functions

 DynamicRangeIterator (THD *thd, TABLE *table, QEP_TAB *qep_tab, ha_rows *examined_rows)
 ~DynamicRangeIterator () 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 ([[maybe_unused]] const IteratorProfiler *profiler)
virtual RowIteratorreal_iterator ()
 If this iterator is wrapping a different iterator (e.g. More...
virtual const RowIteratorreal_iterator () const

Private Attributes

MEM_ROOT m_mem_root
unique_ptr_destroy_only< RowIteratorm_iterator
bool m_quick_traced_before = false
 Used by optimizer tracing to decide whether or not dynamic range analysis of this select has been traced already. More...
ha_rows *const m_examined_rows

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

Constructor & Destructor Documentation

◆ DynamicRangeIterator()

DynamicRangeIterator::DynamicRangeIterator ( THD thd,
TABLE table,
QEP_TAB qep_tab,
ha_rows examined_rows 

◆ ~DynamicRangeIterator()

DynamicRangeIterator::~DynamicRangeIterator ( )

Member Function Documentation

◆ Init()

bool DynamicRangeIterator::Init ( )

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 DynamicRangeIterator::Read ( )

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
-1End of records

Implements RowIterator.

Member Data Documentation

◆ m_examined_rows

ha_rows* const DynamicRangeIterator::m_examined_rows

◆ m_iterator

unique_ptr_destroy_only<RowIterator> DynamicRangeIterator::m_iterator

◆ m_mem_root

MEM_ROOT DynamicRangeIterator::m_mem_root

◆ m_qep_tab

QEP_TAB* DynamicRangeIterator::m_qep_tab

◆ m_quick_traced_before

bool DynamicRangeIterator::m_quick_traced_before = false

Used by optimizer tracing to decide whether or not dynamic range analysis of this select has been traced already.

If optimizer trace option DYNAMIC_RANGE is enabled, range analysis will be traced with different ranges for every record to the left of this table in the join. If disabled, range analysis will only be traced for the first range.

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