Atomic DDL 是 MySQL 8.0 的重要特征之一，关于 Atomic DDL 的介绍文档，流传比较广泛的就是参考文献中提到的两篇文章，文章中对 Atomic DDL 的实现思想和基本过程进行了介绍，建议大家阅读一下。本文尝试对完整的建表/删表过程进行分析。
建表过程
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
| |--> mysql_create_table
| |--> open_tables
| | |--> open_and_process_table
| | | |--> open_table
| | | | |--> check_if_table_exists
| | | | | |--> dd::table_exists
| | | | | | |--> client->acquire
| | | | |
| | | | |--> tc->get_table
| | | | |
| | | | |--> get_table_share_with_discover
| | | | | |--> get_table_share
| | | | | | |--> table_def_cache->find
| | | | | | |--> process_found_table_share
| | | | | | |
| | | | | | |--> alloc_table_share
| | | | | | |--> table_def_cache->emplace
| | | | | | |
| | | | | | |--> thd->dd_client()->acquire
| | | | | | |--> open_table_def
| | | | |
| | | | |--> open_table_from_share
| | | | | |--> ha_open
| | | | | | |--> ha_innobase::open
| | | | | | | |--> lookup_table_handler
| | | | | | | |--> dict_table_check_if_in_cache_low
| | | | | | | |--> dd_open_table
| | | | | | | | |--> dd_open_table_one
| | | | | | | |
| | | | | | | |--> row_create_prebuilt
| | | | | | | |--> info(...)
| | | | | | | | |--> info_low
| | | | | | | | | |--> update_thd
| | | | | | | | | | |--> row_update_prebuilt_trx
| | | | |
| | | | |--> tc->add_used_table
| | | | |
| | | | |--> thd->set_open_tables
| | | | |--> table->init
| |
| |--> mysql_create_table_no_lock
| | |--> create_table_impl
| | | |--> check_engine
| | | |--> set_table_default_charset
| | | |--> get_new_handler
| | | |
| | | |--> check_if_table_exists
| | | |
| | | |--> mysql_prepare_create_table
| | | |
| | | |--> rea_create_base_table
| | | | |--> dd::create_table
| | | | | |--> dict->get_dd_table
| | | | | |--> create_dd_user_table
| | | | | |--> fill_dd_table_from_create_info
| | | | | | |--> fill_dd_columns_from_create_fields
| | | | | | |--> fill_dd_indexes_from_keyinfo
| | | | | | |--> file->get_extra_columns_and_keys
| | | | |
| | | | |--> thd->dd_client()->store
| | | | |--> thd->dd_client()->acquire_for_modification
| | | | |
| | | | |--> ha_create_table
| |
| |--> trans_commit_stmt
| |--> trans_commit_implicit
| | |--> thd->dd_client()->commit_modified_objects
| | | |--> remove_uncommitted_objects
| | | | |--> invalidate
| |
| |--> trans_rollback_stmt
| |--> trans_rollback
| | |--> thd->dd_client()->rollback_modified_objects
| | | |--> remove_uncommitted_objects
| |
| |--> post_ddl
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
| |--> create_impl
| |--> create_table
| | |--> create_table_def
| | | |--> dict_mem_table_create
| | | |--> row_create_table_for_mysql
| | | | |--> dict_build_table_def
| | | | | |--> dict_build_table_space_for_table
| | | | | | |--> log_ddl->write_delete_space_log
| | | | | | |--> fil_ibd_create
| | | | |
| | | | |--> dict_table_add_system_columns
| | | | |
| | | | |--> dict_table_add_to_cache
| | | | |--> log_ddl->write_remove_cache_log
| | |
| | |--> create_index
| | | |--> dict_mem_index_create
| | | |--> row_create_index_for_mysql
| | | | |--> dict_build_index_def
| | | | |
| | | | |--> dict_index_add_to_cache_w_vcol
| | | | | |--> dict_index_build_internal_clust
| | | | | |--> dict_index_build_internal_non_clust
| | | | |
| | | | |--> dict_create_index_tree_in_mem
| | | | | |--> btr_create
| | | | | |--> log_ddl->write_free_tree_log
| |
| |--> create_table_update_global_dd
| | |--> dd_create_implicit_tablespace
| | | |--> dd_create_tablespace
| | | | |--> dd_client->store
| |
| |--> create_table_update_dict
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
|--> acquire
| |--> acquire_uncommitted
| |
| |--> m_registry_committed.get
| |
| |--> Shared_dictionary_cache::instance()->get
| | |--> m_map<T>()->get
| | |
| | |--> get_uncached
| | | |--> Storage_adapter::get
| | | | |--> instance()->core_get
| | | | | |--> m_core_registry.get
| | | | |
| | | | |--> trx.otx.get_table
| | |
| | |--> m_map<T>()->put
| |
| |--> m_registry_committed.put
|--> store
| |--> m_registry_committed.get
| |
| |--> Storage_adapter::store
| | |--> instance()->core_store
| | | |--> m_core_registry.put
| | |
| | |--> object->impl()->store
| | |--> sdi::store
| |
| |--> register_uncommitted_object
| | |--> m_registry_committed.get
| | |--> m_registry_dropped.get
| | |--> m_registry_uncommitted.put
|
删表过程
1
2
3
4
5
6
7
8
| |--> mysql_rm_table
| |--> mysql_rm_table_no_locks
| | |--> drop_base_table
| | | |--> ha_delete_table
| | | |
| | | |--> dd::drop_table
| | |
| | |--> post_ddl
|
1
2
3
4
5
6
7
| |--> delete_impl
| |--> row_drop_table_for_mysql
| | |--> row_drop_table_from_cache
| | |--> log_ddl->write_drop_log
| | |--> log_ddl->write_delete_space_log
| |
| |--> dd_drop_tablespace
|
参考文献
http://mysql.taobao.org/monthly/2018/03/02/
http://mysql.taobao.org/monthly/2018/07/02/