Row versions. More...

#include "data0data.h"
#include "dict0mem.h"
#include "dict0types.h"
#include "lob0undo.h"
#include "mtr0mtr.h"
#include "que0types.h"
#include "rem0types.h"
#include "trx0types.h"
#include "univ.i"
#include "row0vers.ic"

Functions
trx_t *	row_vers_impl_x_locked (const rec_t rec, const dict_index_t index, const ulint *offsets)
	Finds out if an active transaction has inserted or modified a secondary index record. More...

bool	row_vers_must_preserve_del_marked (trx_id_t trx_id, const table_name_t &name, mtr_t *mtr)
	Finds out if we must preserve a delete marked earlier version of a clustered index record, because it is >= the purge view. More...

bool	row_vers_old_has_index_entry (bool also_curr, const rec_t rec, mtr_t mtr, dict_index_t index, const dtuple_t ientry, roll_ptr_t roll_ptr, trx_id_t trx_id)
	Finds out if a version of the record, where the version >= the current purge view, should have ientry as its secondary index entry. More...

dberr_t	row_vers_build_for_consistent_read (const rec_t rec, mtr_t mtr, dict_index_t index, ulint offsets, ReadView view, mem_heap_t *offset_heap, mem_heap_t in_heap, rec_t old_vers, const dtuple_t vrow, lob::undo_vers_t *lob_undo)
	Constructs the version of a clustered index record which a consistent read should see. More...

void	row_vers_build_for_semi_consistent_read (const rec_t rec, mtr_t mtr, dict_index_t index, ulint offsets, mem_heap_t offset_heap, mem_heap_t in_heap, const rec_t old_vers, const dtuple_t vrow)
	Constructs the last committed version of a clustered index record, which should be seen by a semi-consistent read. More...

Detailed Description

Row versions.

Created 2/6/1997 Heikki Tuuri

Function Documentation

◆ row_vers_build_for_consistent_read()

dberr_t row_vers_build_for_consistent_read	(	const rec_t *	rec,
		mtr_t *	mtr,
		dict_index_t *	index,
		ulint **	offsets,
		ReadView *	view,
		mem_heap_t **	offset_heap,
		mem_heap_t *	in_heap,
		rec_t **	old_vers,
		const dtuple_t **	vrow,
		lob::undo_vers_t *	lob_undo
	)

Constructs the version of a clustered index record which a consistent read should see.

We assume that the trx id stored in rec is such that the consistent read should not see rec in its present version.

Parameters

[in]	rec	record in a clustered index; the caller must have a latch on the page; this latch locks the top of the stack of versions of this records
[in]	mtr	mtr holding the latch on rec; it will also hold the latch on purge_view
[in]	index	the clustered index
[in]	offsets	offsets returned by rec_get_offsets(rec, index)
[in]	view	the consistent read view
[in,out]	offset_heap	memory heap from which the offsets are allocated
[in]	in_heap	memory heap from which the memory for *old_vers is allocated; memory for possible intermediate versions is allocated and freed locally within the function
[out]	old_vers	old version, or NULL if the history is missing or the record does not exist in the view, that is, it was freshly inserted afterwards.
[out]	vrow	reports virtual column info if any
[in]	lob_undo	undo log to be applied to blobs.

Returns: DB_SUCCESS or DB_MISSING_HISTORY

◆ row_vers_build_for_semi_consistent_read()

void row_vers_build_for_semi_consistent_read	(	const rec_t *	rec,
		mtr_t *	mtr,
		dict_index_t *	index,
		ulint **	offsets,
		mem_heap_t **	offset_heap,
		mem_heap_t *	in_heap,
		const rec_t **	old_vers,
		const dtuple_t **	vrow
	)

Constructs the last committed version of a clustered index record, which should be seen by a semi-consistent read.

Parameters

[in]	rec	Record in a clustered index; the caller must have a latch on the page; this latch locks the top of the stack of versions of this records
[in]	mtr	Mini-transaction holding the latch on rec
[in]	index	The clustered index
[in,out]	offsets	Offsets returned by rec_get_offsets(rec, index)
[in,out]	offset_heap	Memory heap from which the offsets are allocated
[in]	in_heap	Memory heap from which the memory for *old_vers is allocated; memory for possible intermediate versions is allocated and freed locally within the function
[out]	old_vers	Rec, old version, or null if the record does not exist in the view, that is, it was freshly inserted afterwards
[out]	vrow	Virtual row, old version, or null if it is not updated in the view

◆ row_vers_impl_x_locked()

trx_t * row_vers_impl_x_locked	(	const rec_t *	rec,
		const dict_index_t *	index,
		const ulint *	offsets
	)

Finds out if an active transaction has inserted or modified a secondary index record.

Parameters

[in]	rec	record in a secondary index
[in]	index	the secondary index
[in]	offsets	rec_get_offsets(rec, index)

Returns: 0 if committed, else the active transaction id; NOTE that this function can return false positives but never false negatives. The caller must confirm all positive results by checking if the trx is still active.

◆ row_vers_must_preserve_del_marked()

bool row_vers_must_preserve_del_marked	(	trx_id_t	trx_id,
		const table_name_t &	name,
		mtr_t *	mtr
	)

Finds out if we must preserve a delete marked earlier version of a clustered index record, because it is >= the purge view.

Parameters

[in]	trx_id	Transaction id in the version
[in]	name	Table name
[in,out]	mtr	Mini-transaction holding the latch on the clustered index record; it will also hold the latch on purge_view

Returns: true if earlier version should be preserved

◆ row_vers_old_has_index_entry()

bool row_vers_old_has_index_entry	(	bool	also_curr,
		const rec_t *	rec,
		mtr_t *	mtr,
		dict_index_t *	index,
		const dtuple_t *	ientry,
		roll_ptr_t	roll_ptr,
		trx_id_t	trx_id
	)

Finds out if a version of the record, where the version >= the current purge view, should have ientry as its secondary index entry.

We check if there is any not delete marked version of the record where the trx id >= purge view, and the secondary index entry == ientry; exactly in this case we return true.

Returns: true if earlier version should have in: transaction ID on the purging record

We check if there is any not delete marked version of the record where the trx id >= purge view, and the secondary index entry and ientry are identified in the alphabetical ordering; exactly in this case we return true.

Returns: true if earlier version should have

Parameters

also_curr	in: true if also rec is included in the versions to search; otherwise only versions prior to it are searched
rec	in: record in the clustered index; the caller must have a latch on the page
mtr	in: mtr holding the latch on rec; it will also hold the latch on purge_view
index	in: the secondary index
ientry	in: the secondary index entry
roll_ptr	in: roll_ptr for the purge record
trx_id	in: transaction ID on the purging record

Functions

Detailed Description

Function Documentation

◆ row_vers_build_for_consistent_read()

◆ row_vers_build_for_semi_consistent_read()

◆ row_vers_impl_x_locked()

◆ row_vers_must_preserve_del_marked()

◆ row_vers_old_has_index_entry()