MySQL  8.0.19
Source Code Documentation
row0purge.h
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26 
27 /** @file include/row0purge.h
28  Purge obsolete records
29 
30  Created 3/14/1997 Heikki Tuuri
31  *******************************************************/
32 
33 #ifndef row0purge_h
34 #define row0purge_h
35 
36 #include "univ.i"
37 
38 #include "btr0pcur.h"
39 #include "btr0types.h"
40 #include "data0data.h"
41 #include "dict0types.h"
42 #include "que0types.h"
43 #include "row0types.h"
44 #include "trx0types.h"
45 #include "ut0vec.h"
46 
47 /** Create a purge node to a query graph.
48 @param[in] parent parent node, i.e., a thr node
49 @param[in] heap memory heap where created
50 @return own: purge node */
52  MY_ATTRIBUTE((warn_unused_result));
53 
54 /** Determines if it is possible to remove a secondary index entry.
55  Removal is possible if the secondary index entry does not refer to any
56  not delete marked version of a clustered index record where DB_TRX_ID
57  is newer than the purge view.
58 
59  NOTE: This function should only be called by the purge thread, only
60  while holding a latch on the leaf page of the secondary index entry
61  (or keeping the buffer pool watch on the page). It is possible that
62  this function first returns true and then false, if a user transaction
63  inserts a record that the secondary index entry would refer to.
64  However, in that case, the user transaction would also re-insert the
65  secondary index entry after purge has removed it and released the leaf
66  page latch.
67  @return true if the secondary index record can be purged */
68 bool row_purge_poss_sec(purge_node_t *node, /*!< in/out: row purge node */
69  dict_index_t *index, /*!< in: secondary index */
70  const dtuple_t *entry) /*!< in: secondary index entry */
71  MY_ATTRIBUTE((warn_unused_result));
72 /***************************************************************
73 Does the purge operation for a single undo log record. This is a high-level
74 function used in an SQL execution graph.
75 @return query thread to run next or NULL */
76 que_thr_t *row_purge_step(que_thr_t *thr) /*!< in: query thread */
77  MY_ATTRIBUTE((warn_unused_result));
78 
79 /* Purge node structure */
80 
81 struct purge_node_t {
82  /** Info required to purge a record */
83  struct rec_t {
84  /** Record to purge */
86 
87  /** File pointer to UNDO record */
89 
90  /** Trx that created this undo record */
92  };
93 
94  using Recs = std::list<rec_t, mem_heap_allocator<rec_t>>;
95 
96  /** node type: QUE_NODE_PURGE */
98 
99  /* Local storage for this graph node */
100 
101  /** roll pointer to undo log record */
103 
104  /** undo number of the record */
106 
107  /** undo log record type: TRX_UNDO_INSERT_REC, ... */
108  ulint rec_type;
109 
110  /** table where purge is done */
112 
113  /** MDL ticket for the table name */
115 
116  /** parent table for an FTS AUX TABLE */
118 
119  /** MDL ticket for the parent table of an FTS AUX TABLE */
121 
122  /** MySQL table instance */
124 
125  /** compiler analysis info of an update */
126  ulint cmpl_info;
127 
128  /** update vector for a clustered index record */
130 
131  /** NULL, or row reference to the next row to handle */
133 
134  /** NULL, or a copy (also fields copied to heap) of the indexed
135  fields of the row to handle */
137 
138  /** NULL, or the next index whose record should be handled */
140 
141  /** The heap is owned by purge_sys and is reset after a purge
142  batch has completed. */
144 
145  /** true if the clustered index record determined by ref was
146  found in the clustered index, and we were able to position pcur on it */
148 
149  /** persistent cursor used in searching the clustered index record */
151 
152  /** Debug flag */
153  bool done;
154 
155  /** trx id for this purging record */
157 
158  /** trx id for this purging record */
160 
161  /** Undo recs to purge */
163 
164  /** Check if undo records of given table_id is there in this purge node.
165  @param[in] table_id look for undo records of this table id.
166  @return true if undo records of table id exists, false otherwise. */
167  bool is_table_id_exists(table_id_t table_id) const;
168 
169 #ifdef UNIV_DEBUG
170  /** Check if there are more than one undo record with same (trx_id, undo_no)
171  combination.
172  @return true when no duplicates are found, false otherwise. */
173  bool check_duplicate_undo_no() const;
174 #endif /* UNIV_DEBUG */
175 
177 #ifdef UNIV_DEBUG
178  /** Validate the persisent cursor. The purge node has two references
179  to the clustered index record - one via the ref member, and the
180  other via the persistent cursor. These two references must match
181  each other if the found_clust flag is set.
182  @return true if the persistent cursor is consistent with
183  the ref member.*/
184  bool validate_pcur();
185 #endif
186 };
187 
188 #include "row0purge.ic"
189 
190 #endif
roll_ptr_t
ib_id_t roll_ptr_t
Rollback pointer (DB_ROLL_PTR, DATA_ROLL_PTR)
Definition: trx0types.h:150
dtuple_t
Structure for an SQL data tuple of fields (logical record)
Definition: data0data.h:716
btr_pcur_t
Definition: btr0pcur.h:177
purge_node_t::mysql_table
TABLE * mysql_table
MySQL table instance.
Definition: row0purge.h:123
dict0types.h
undo_no_t
ib_id_t undo_no_t
Undo number.
Definition: trx0types.h:152
trx_id_t
ib_id_t trx_id_t
Transaction identifier (DB_TRX_ID, DATA_TRX_ID)
Definition: trx0types.h:148
purge_node_t
Definition: row0purge.h:81
purge_node_t::is_table_id_exists
bool is_table_id_exists(table_id_t table_id) const
Check if undo records of given table_id is there in this purge node.
Definition: row0purge.cc:1297
purge_node_t::ref
dtuple_t * ref
NULL, or row reference to the next row to handle.
Definition: row0purge.h:132
purge_node_t::table
dict_table_t * table
table where purge is done
Definition: row0purge.h:111
purge_node_t::pcur
btr_pcur_t pcur
persistent cursor used in searching the clustered index record
Definition: row0purge.h:150
dict_index_t
Data structure for an index.
Definition: dict0mem.h:869
purge_node_t::roll_ptr
roll_ptr_t roll_ptr
roll pointer to undo log record
Definition: row0purge.h:102
TABLE
Definition: table.h:1305
purge_node_t::done
bool done
Debug flag.
Definition: row0purge.h:153
purge_node_t::heap
mem_heap_t * heap
The heap is owned by purge_sys and is reset after a purge batch has completed.
Definition: row0purge.h:143
purge_node_t::trx_id
trx_id_t trx_id
trx id for this purging record
Definition: row0purge.h:156
dict_table_t
Data structure for a database table.
Definition: dict0mem.h:1510
purge_node_t::update
upd_t * update
update vector for a clustered index record
Definition: row0purge.h:129
purge_node_t::rec_t::roll_ptr
roll_ptr_t roll_ptr
File pointer to UNDO record.
Definition: row0purge.h:88
purge_node_t::row
dtuple_t * row
NULL, or a copy (also fields copied to heap) of the indexed fields of the row to handle.
Definition: row0purge.h:136
que0types.h
mem_block_info_t
The info structure stored at the beginning of a heap block.
Definition: mem0mem.h:337
trx_rseg_t
The rollback segment memory object.
Definition: trx0types.h:187
purge_node_t::recs
Recs * recs
Undo recs to purge.
Definition: row0purge.h:162
row_purge_node_create
purge_node_t * row_purge_node_create(que_thr_t *parent, mem_heap_t *heap)
Create a purge node to a query graph.
Definition: row0purge.cc:79
purge_node_t::rec_t::modifier_trx_id
trx_id_t modifier_trx_id
Trx that created this undo record.
Definition: row0purge.h:91
purge_node_t::rec_t::undo_rec
trx_undo_rec_t * undo_rec
Record to purge.
Definition: row0purge.h:85
purge_node_t::modifier_trx_id
trx_id_t modifier_trx_id
trx id for this purging record
Definition: row0purge.h:159
table_id_t
ib_id_t table_id_t
Table or partition identifier (unique within an InnoDB instance).
Definition: dict0types.h:215
row0types.h
btr0types.h
purge_node_t::rec_type
ulint rec_type
undo log record type: TRX_UNDO_INSERT_REC, ...
Definition: row0purge.h:108
purge_node_t::index
dict_index_t * index
NULL, or the next index whose record should be handled.
Definition: row0purge.h:139
trx0types.h
row_purge_step
que_thr_t * row_purge_step(que_thr_t *thr)
Does the purge operation for a single undo log record.
Definition: row0purge.cc:1209
btr0pcur.h
que_common_t
Definition: que0types.h:50
purge_node_t::Recs
std::list< rec_t, mem_heap_allocator< rec_t > > Recs
Definition: row0purge.h:94
purge_node_t::rseg
trx_rseg_t * rseg
Definition: row0purge.h:176
ut0vec.h
purge_node_t::found_clust
bool found_clust
true if the clustered index record determined by ref was found in the clustered index,...
Definition: row0purge.h:147
purge_node_t::parent_mdl
MDL_ticket * parent_mdl
MDL ticket for the parent table of an FTS AUX TABLE.
Definition: row0purge.h:120
purge_node_t::parent
dict_table_t * parent
parent table for an FTS AUX TABLE
Definition: row0purge.h:117
_entry
Definition: completion_hash.h:34
purge_node_t::cmpl_info
ulint cmpl_info
compiler analysis info of an update
Definition: row0purge.h:126
purge_node_t::common
que_common_t common
node type: QUE_NODE_PURGE
Definition: row0purge.h:97
purge_node_t::mdl
MDL_ticket * mdl
MDL ticket for the table name.
Definition: row0purge.h:114
purge_node_t::rec_t
Info required to purge a record.
Definition: row0purge.h:83
purge_node_t::undo_no
undo_no_t undo_no
undo number of the record
Definition: row0purge.h:105
purge_node_t::validate_pcur
bool validate_pcur()
Validate the persisent cursor.
Definition: row0purge.cc:1258
upd_t
Definition: row0upd.h:570
row_purge_poss_sec
bool row_purge_poss_sec(purge_node_t *node, dict_index_t *index, const dtuple_t *entry)
Determines if it is possible to remove a secondary index entry.
Definition: row0purge.cc:270
data0data.h
trx_undo_rec_t
byte trx_undo_rec_t
Undo log record.
Definition: trx0types.h:177
purge_node_t::check_duplicate_undo_no
bool check_duplicate_undo_no() const
Check if there are more than one undo record with same (trx_id, undo_no) combination.
Definition: row0purge.cc:1315
MDL_ticket
A granted metadata lock.
Definition: mdl.h:963
que_thr_t
Definition: que0que.h:246
index
char * index(const char *, int c)
Definition: mysql.cc:2875