MySQL 8.0.31
Source Code Documentation
IndexMergeIterator Class Reference

#include <index_merge.h>

Inheritance diagram for IndexMergeIterator:
[legend]

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 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

unique_ptr_destroy_only< Uniqueunique
 
unique_ptr_destroy_only< RowIteratorread_record
 
unique_ptr_destroy_only< RowIteratorpk_quick_select
 
Mem_root_array< unique_ptr_destroy_only< RowIterator > > m_children
 
bool doing_pk_scan
 
MEM_ROOTmem_root
 

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

◆ 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 TABLE_REF) 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
0OK
-1End of records
1Error

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

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