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/*****************************************************************************
Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/row0purge.h
Purge obsolete records
Created 3/14/1997 Heikki Tuuri
*******************************************************/
#ifndef row0purge_h
#define row0purge_h
#include "univ.i"
#include "data0data.h"
#include "btr0types.h"
#include "btr0pcur.h"
#include "dict0types.h"
#include "trx0types.h"
#include "que0types.h"
#include "row0types.h"
#include "ut0vec.h"
/** Create a purge node to a query graph.
@param[in] parent parent node, i.e., a thr node
@param[in] heap memory heap where created
@return own: purge node */
purge_node_t*
row_purge_node_create(
que_thr_t* parent,
mem_heap_t* heap)
MY_ATTRIBUTE((warn_unused_result));
/***********************************************************//**
Determines if it is possible to remove a secondary index entry.
Removal is possible if the secondary index entry does not refer to any
not delete marked version of a clustered index record where DB_TRX_ID
is newer than the purge view.
NOTE: This function should only be called by the purge thread, only
while holding a latch on the leaf page of the secondary index entry
(or keeping the buffer pool watch on the page). It is possible that
this function first returns true and then false, if a user transaction
inserts a record that the secondary index entry would refer to.
However, in that case, the user transaction would also re-insert the
secondary index entry after purge has removed it and released the leaf
page latch.
@return true if the secondary index record can be purged */
bool
row_purge_poss_sec(
/*===============*/
purge_node_t* node, /*!< in/out: row purge node */
dict_index_t* index, /*!< in: secondary index */
const dtuple_t* entry) /*!< in: secondary index entry */
MY_ATTRIBUTE((nonnull, warn_unused_result));
/***************************************************************
Does the purge operation for a single undo log record. This is a high-level
function used in an SQL execution graph.
@return query thread to run next or NULL */
que_thr_t*
row_purge_step(
/*===========*/
que_thr_t* thr) /*!< in: query thread */
MY_ATTRIBUTE((nonnull, warn_unused_result));
/* Purge node structure */
struct purge_node_t{
que_common_t common; /*!< node type: QUE_NODE_PURGE */
/*----------------------*/
/* Local storage for this graph node */
roll_ptr_t roll_ptr;/* roll pointer to undo log record */
ib_vector_t* undo_recs;/*!< Undo recs to purge */
undo_no_t undo_no;/*!< undo number of the record */
ulint rec_type;/*!< undo log record type: TRX_UNDO_INSERT_REC,
... */
dict_table_t* table; /*!< table where purge is done */
ulint cmpl_info;/* compiler analysis info of an update */
upd_t* update; /*!< update vector for a clustered index
record */
const dtuple_t* ref; /*!< NULL, or row reference to the next row to
handle */
dtuple_t* row; /*!< NULL, or a copy (also fields copied to
heap) of the indexed fields of the row to
handle */
dict_index_t* index; /*!< NULL, or the next index whose record should
be handled */
mem_heap_t* heap; /*!< memory heap used as auxiliary storage for
row; this must be emptied after a successful
purge of a row */
ibool found_clust;/* TRUE if the clustered index record
determined by ref was found in the clustered
index, and we were able to position pcur on
it */
btr_pcur_t pcur; /*!< persistent cursor used in searching the
clustered index record */
ibool done; /* Debug flag */
trx_id_t trx_id; /*!< trx id for this purging record */
#ifdef UNIV_DEBUG
/***********************************************************//**
Validate the persisent cursor. The purge node has two references
to the clustered index record - one via the ref member, and the
other via the persistent cursor. These two references must match
each other if the found_clust flag is set.
@return true if the persistent cursor is consistent with
the ref member.*/
bool validate_pcur();
#endif
};
#endif
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