MySQL 8.0.31
Source Code Documentation
update_rows_iterator.h
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1#ifndef SQL_ITERATORS_UPDATE_ROWS_ITERATOR_H_
2#define SQL_ITERATORS_UPDATE_ROWS_ITERATOR_H_
3
4/* Copyright (c) 2022, Oracle and/or its affiliates.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License, version 2.0,
8 as published by the Free Software Foundation.
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15 separately licensed software that they have included with MySQL.
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19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License, version 2.0, for more details.
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25
26#include <cassert>
27#include <memory>
28
29#include "my_alloc.h"
30#include "my_base.h"
31#include "my_table_map.h"
33#include "sql/sql_list.h"
34
35class COPY_INFO;
36class Copy_field;
37class Item;
38class THD;
39struct TABLE;
40struct TABLE_LIST;
41template <class T>
42class mem_root_deque;
43
44/// An iterator that performs updates to rows returned by its child iterator.
45class UpdateRowsIterator final : public RowIterator {
46 public:
48 TABLE *outermost_table, TABLE *immediate_table,
49 TABLE_LIST *update_tables, TABLE **tmp_tables,
51 List<TABLE> unupdated_check_opt_tables,
52 COPY_INFO **update_operations,
53 mem_root_deque<Item *> **fields_for_table,
54 mem_root_deque<Item *> **values_for_table,
55 table_map tables_with_rowid_in_buffer);
56 ~UpdateRowsIterator() override;
57 bool Init() override;
58 int Read() override;
59 void StartPSIBatchMode() override { m_source->StartPSIBatchMode(); }
60 void EndPSIBatchModeIfStarted() override {
61 m_source->EndPSIBatchModeIfStarted();
62 }
63 void SetNullRowFlag([[maybe_unused]] bool is_null_row) override {
64 assert(false);
65 }
66 void UnlockRow() override { assert(false); }
67 ha_rows found_rows() const { return m_found_rows; }
69
70 private:
71 /// The iterator producing the rows to update.
73 /// The outermost table of the join. It may or may not be one of the tables
74 /// being updated.
76 /// The table to perform immediate update on, or nullptr if immediate update
77 /// is not possible.
79 /// Pointer to list of updated tables, linked via 'next_local'.
81 /// Temporary tables used to store cached updates.
83 /// Objects that copy the updated values from a temporary table to the update
84 /// target table, and perform conversions if the types differ.
86 /// Tables referenced in the CHECK OPTION condition of the updated view
87 /// excluding the updated table.
89 /// The update operations of each table in m_update_tables (indexed in the
90 /// same order as m_update_tables).
92 /// The fields list decomposed into separate lists per table.
94 /// The values list decomposed into separate lists per table.
96 /// The number of rows matching the WHERE and join conditions.
98 /// The number of rows actually updated.
100 /// All the tables that are part of a hash join. We use this map to find out
101 /// how to get the row ID from a table when buffering row IDs for delayed
102 /// update. For those tables that are part of a hash join, the row ID will
103 /// already be available in handler::ref, and calling handler::position() will
104 /// overwrite it with an incorrect row ID (most likely the last row read from
105 /// the table). For those that are not part of a hash join,
106 /// handler::position() must be called to get the current row ID from the
107 /// underlying scan.
109
110 /// Perform all the immediate updates for the current row returned by the
111 /// join, and buffer row IDs for the non-immediate tables.
112 ///
113 /// @param[out] trans_safe Gets set to false if a non-transactional table
114 /// is updated.
115 /// @param[out] transactional_tables Gets set to true if a transactional
116 /// table is updated.
117 /// @return True on error.
118 bool DoImmediateUpdatesAndBufferRowIds(bool *trans_safe,
119 bool *transactional_tables);
120
121 /// Perform all the delayed updates.
122 ///
123 /// @param[in,out] trans_safe Gets set to false if a non-transactional table
124 /// is updated.
125 /// @param[out] transactional_tables Gets set to true if a transactional
126 /// table is updated.
127 /// @return True on error.
128 bool DoDelayedUpdates(bool *trans_safe, bool *transactional_tables);
129};
130
131#endif // SQL_ITERATORS_UPDATE_ROWS_ITERATOR_H_
This class encapsulates a data change operation.
Definition: sql_data_change.h:73
Definition: field.h:4572
Base class that is used to represent any kind of expression in a relational query.
Definition: item.h:802
Definition: sql_list.h:433
A context for reading through a single table using a chosen access method: index read,...
Definition: row_iterator.h:81
THD * thd() const
Definition: row_iterator.h:227
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:922
An iterator that performs updates to rows returned by its child iterator.
Definition: update_rows_iterator.h:45
ha_rows updated_rows() const
Definition: update_rows_iterator.h:68
COPY_INFO ** m_update_operations
The update operations of each table in m_update_tables (indexed in the same order as m_update_tables)...
Definition: update_rows_iterator.h:91
Copy_field * m_copy_fields
Objects that copy the updated values from a temporary table to the update target table,...
Definition: update_rows_iterator.h:85
TABLE * m_immediate_table
The table to perform immediate update on, or nullptr if immediate update is not possible.
Definition: update_rows_iterator.h:78
mem_root_deque< Item * > ** m_fields_for_table
The fields list decomposed into separate lists per table.
Definition: update_rows_iterator.h:93
table_map m_hash_join_tables
All the tables that are part of a hash join.
Definition: update_rows_iterator.h:108
int Read() override
Read a single row.
Definition: sql_update.cc:2856
bool DoDelayedUpdates(bool *trans_safe, bool *transactional_tables)
Perform all the delayed updates.
Definition: sql_update.cc:2576
mem_root_deque< Item * > ** m_values_for_table
The values list decomposed into separate lists per table.
Definition: update_rows_iterator.h:95
TABLE_LIST * m_update_tables
Pointer to list of updated tables, linked via 'next_local'.
Definition: update_rows_iterator.h:80
ha_rows m_found_rows
The number of rows matching the WHERE and join conditions.
Definition: update_rows_iterator.h:97
bool DoImmediateUpdatesAndBufferRowIds(bool *trans_safe, bool *transactional_tables)
Perform all the immediate updates for the current row returned by the join, and buffer row IDs for th...
Definition: sql_update.cc:2412
void StartPSIBatchMode() override
Start performance schema batch mode, if supported (otherwise ignored).
Definition: update_rows_iterator.h:59
~UpdateRowsIterator() override
Definition: sql_update.cc:2850
UpdateRowsIterator(THD *thd, unique_ptr_destroy_only< RowIterator > source, TABLE *outermost_table, TABLE *immediate_table, TABLE_LIST *update_tables, TABLE **tmp_tables, Copy_field *copy_fields, List< TABLE > unupdated_check_opt_tables, COPY_INFO **update_operations, mem_root_deque< Item * > **fields_for_table, mem_root_deque< Item * > **values_for_table, table_map tables_with_rowid_in_buffer)
Definition: sql_update.cc:3034
TABLE * m_outermost_table
The outermost table of the join.
Definition: update_rows_iterator.h:75
ha_rows m_updated_rows
The number of rows actually updated.
Definition: update_rows_iterator.h:99
bool Init() override
Initialize or reinitialize the iterator.
Definition: sql_update.cc:2835
List< TABLE > m_unupdated_check_opt_tables
Tables referenced in the CHECK OPTION condition of the updated view excluding the updated table.
Definition: update_rows_iterator.h:88
TABLE ** m_tmp_tables
Temporary tables used to store cached updates.
Definition: update_rows_iterator.h:82
ha_rows found_rows() const
Definition: update_rows_iterator.h:67
unique_ptr_destroy_only< RowIterator > m_source
The iterator producing the rows to update.
Definition: update_rows_iterator.h:72
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...
Definition: update_rows_iterator.h:63
void EndPSIBatchModeIfStarted() override
Ends performance schema batch mode, if started.
Definition: update_rows_iterator.h:60
void UnlockRow() override
Definition: update_rows_iterator.h:66
A (partial) implementation of std::deque allocating its blocks on a MEM_ROOT.
Definition: mem_root_deque.h:109
bool copy_fields(Temp_table_param *param, const THD *thd, bool reverse_copy)
Make a copy of all simple SELECT'ed fields.
Definition: sql_executor.cc:4229
This file follows Google coding style, except for the name MEM_ROOT (which is kept for historical rea...
std::unique_ptr< T, Destroy_only< T > > unique_ptr_destroy_only
std::unique_ptr, but only destroying.
Definition: my_alloc.h:488
This file includes constants used by all storage engines.
my_off_t ha_rows
Definition: my_base.h:1139
uint64_t table_map
Definition: my_table_map.h:29
repeated Source source
Definition: replication_asynchronous_connection_failover.proto:41
Definition: table.h:2756
Definition: table.h:1396