undo_truncate::Truncate Class Reference

Track an UNDO tablespace marked for truncate. More...

#include <trx0undo_trunc.h>

Public Member Functions
	Truncate ()
	Constructor. More...
	~Truncate ()=default
	Destructor. More...
bool	is_marked () const
	Is tablespace selected for truncate. More...
void	set_marked_space_empty ()
	Mark the undo tablespace selected for truncate as empty so that it will be truncated next. More...
bool	is_marked_space_empty () const
	Is the tablespace selected for truncate empty of undo logs yet? More...
void	mark (Tablespace *undo_space)
	Mark the tablespace for truncate. More...
space_id_t	get_marked_space_num () const
	Get the number of the tablespace marked for truncate. More...
void	reset ()
	Reset for next rseg truncate. More...
space_id_t	get_scan_space_num () const
	Get the undo tablespace number to start a scan. More...
space_id_t	increment_scan () const
	Increment the scanning position in a round-robin fashion. More...
bool	is_equal (space_id_t space_id) const
	Check if the given space id is equal to the space ID that is marked for truncation. More...
int64_t	check_timer () const
void	reset_timer ()
	Reset the timer. More...

Private Attributes
space_id_t	m_space_id_marked
	UNDO space ID that is marked for truncate. More...
bool	m_marked_space_is_empty
	This is true if the marked space is empty of undo logs and ready to truncate. More...
ib::Timer	m_timer
	Elapsed time since last truncate check. More...

Static Private Attributes
static size_t	s_scan_pos
	Start scanning for UNDO tablespace from this vector position. More...

Detailed Description

Track an UNDO tablespace marked for truncate.

Constructor & Destructor Documentation

Truncate()

undo_truncate::Truncate::Truncate ( )

inline

Constructor.

~Truncate()

undo_truncate::Truncate::~Truncate ( )

default

Destructor.

Member Function Documentation

check_timer()

int64_t undo_truncate::Truncate::check_timer ( ) const

inline

Returns

the number of milliseconds since last reset.

get_marked_space_num()

space_id_t undo_truncate::Truncate::get_marked_space_num ( ) const

inline

Get the number of the tablespace marked for truncate.

Returns

tablespace number marked for truncate.

get_scan_space_num()

space_id_t undo_truncate::Truncate::get_scan_space_num ( ) const

inline

Get the undo tablespace number to start a scan.

Re-adjust in case the spaces::size() went down.

Returns

undo space_num to start scanning.

increment_scan()

space_id_t undo_truncate::Truncate::increment_scan ( ) const

inline

Increment the scanning position in a round-robin fashion.

Returns

undo space_num at incremented scanning position.

Round-robin way of selecting an undo tablespace for the truncate operation. Once we reach the end of the list of known undo tablespace IDs, move back to the first undo tablespace ID. This will scan active as well as inactive undo tablespaces.

is_equal()

bool undo_truncate::Truncate::is_equal ( space_id_t  space_id ) const

inline

Check if the given space id is equal to the space ID that is marked for truncation.

Returns

true if they are equal, false otherwise.

is_marked()

bool undo_truncate::Truncate::is_marked ( ) const

inline

Is tablespace selected for truncate.

Returns

true if undo tablespace is marked for truncate

is_marked_space_empty()

bool undo_truncate::Truncate::is_marked_space_empty ( ) const

inline

Is the tablespace selected for truncate empty of undo logs yet?

Returns

true if the marked undo tablespace has no more undo logs

mark()

void undo_truncate::Truncate::mark

(

Tablespace *

undo_space

)

Mark the tablespace for truncate.

Parameters

[in]

undo_space

undo tablespace to truncate.

reset()

void undo_truncate::Truncate::reset ( void  )

inline

Reset for next rseg truncate.

reset_timer()

void undo_truncate::Truncate::reset_timer ( )

inline

Reset the timer.

set_marked_space_empty()

void undo_truncate::Truncate::set_marked_space_empty ( )

inline

Mark the undo tablespace selected for truncate as empty so that it will be truncated next.

Member Data Documentation

m_marked_space_is_empty

bool undo_truncate::Truncate::m_marked_space_is_empty

private

This is true if the marked space is empty of undo logs and ready to truncate.

We leave the rsegs object 'inactive' until after it is truncated and rebuilt. This allow the code to do the check for undo logs only once.

m_space_id_marked

space_id_t undo_truncate::Truncate::m_space_id_marked

private

UNDO space ID that is marked for truncate.

m_timer

ib::Timer undo_truncate::Truncate::m_timer

private

Elapsed time since last truncate check.

s_scan_pos

size_t undo_truncate::Truncate::s_scan_pos

staticprivate

Start scanning for UNDO tablespace from this vector position.

This is to avoid bias selection of one tablespace always.

---

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

• storage/innobase/include/trx0undo_trunc.h
• storage/innobase/trx/trx0purge.cc