mariadb/include
Nikita Malyavin 8e1077b621 MDEV-35915 Implement Global temporary tables
Global temporary table (GTT) is a table with globally defined metadata,
but per-session data.

That is, the life duration of this data is limited with session
duration. Here we have two options:

1. ON COMMIT DELETE ROWS: a default option. The life duration of data is
transaction duration.
2. ON COMMIT PRESERVE ROWS: The life duration of data is session
duration.

# Implementation

The implementation consists of the following fundamental parts.

## Part 1: CREATE TABLE + frm format

1. Store GLOBAL TEMPORARY and ON COMMIT bits in
   create_info->table_options
2. Store higher word of create_info->table_options in frm header
3. Also disallow ON COMMIT keyword for (local) temporary tables

As a result, the bits will be available in share->db_create_options.

New Table_type enum element: TABLE_TYPE_GLOBAL_TEMPORARY (datadict.h)

## Part 2: open_table: a local data table is created on demand

On open, a session-local temporary table copy is created from a global
TABLE_SHARE. Let us refer to the former as "local data table of GTT",
and the latter as "global metadata table of GTT".

There is a number of cases, when a global metadata table is opened
instead, like ALTER, DROP, SHOW CREATE

A local data table holds:

1. A reference to that share, and holds the increased
tdc reference count.
2. An explicit MDL lock to the duration of local copy's
existence.

While at least one local data table exists
(2) guarantees that ALTER, DROP or RENAME will not happen.
(1) guarantees that a global metadata table will not be flushed

At an implementation level, a local data table is a temporary table,
invisible for a user and augmented with (1) and (2).

The reference and lock are released upon dropping this local data table,
which happens due to:
a) TRUNCATE TABLE
b) Connection close
c) If ON COMMIT DELETE ROWS is used, then on transaction commit/rollback

## Part 3: ALTER, DROP, RENAME

These operations always open a real global temporary table.

ALTER, RENAME and DROP TABLE require all local data tables to be
destroyed, thus, having no references to a modified/deleted table.
For that, they:
1. acquire an EXCLUSIVE MDL lock. To match oracle behavior,
lock_wait_timeout is 0 in ALTER TABLE.
2. Check that there is no matching local temporary table in the same
connection (which is not guaranteed by 1)

## Part 4 ON COMMIT DELETE ROWS

This clause is assumed by default, i.e. it is implicit.

When ON COMMIT DELETE ROWS, the local data table is dropped on
commit/rollback.

On table open, global_temporary_tables handlerton is injected,
implementing this behavior.

# Limitations

The following is forbidden for GTT:
system versioning
partitioning
fk
ONLINE ALTER
CREATE GLOBAL TEMPORARY under LOCK TABLES
FLUSH TABLE on Global temporary table is no-op for now

# Refactorings, details

1. Extract drop_tmp_table_share (temporary_tables.cc)
2. Extract THD::open_temporary_table_impl (temporary_tables.cc)
3. information_schema support:
 x) "GLOBAL TEMPORARY" type is show in information_schema.tables
 y) an artifical temporary table is hidden from SHOW TABLE STATUS

4. VIEWs are supported.
5. AS SELECT support

 x) Made in Oracle style, so that the data is only inserted in the
 session that creates GTT
 y) ON COMMIT DELETE ROWS inserts the data for real, and then deletes
 the data table on implicit commit

6. CREATE TABLE ... LIKE is supported.

7. Replication support
 x) Set share->table_creation_was_logged to 0 to make the table ignored
 for replication.
 y) Statements with GTT involved will be logged in Row-based style
 (RBR)
 z) Global temporary table creation and alter/drop will be logged.
2025-07-31 02:45:40 +02:00
..
atomic MDEV-25870 followup - some Windows ARM64 improvements 2023-09-24 11:20:38 +02:00
mysql MDEV-12182 post-merge 2025-05-02 13:56:25 +02:00
providers support lzma < 5.1.3alpha 2022-02-09 19:13:52 +01:00
aligned.h Revert aligned_alloc() addition from MDEV-28836 2022-08-22 09:10:40 +03:00
aria_backup.h S3 is pluggable now 2020-06-19 19:43:07 +02:00
assume_aligned.h Remove a misleading copyright message 2020-03-21 10:25:54 +02:00
big_endian.h MDEV-34970 Vector search fails to compile on s390x 2024-11-05 14:00:50 -08:00
byte_order_generic.h Fix all warnings given by UBSAN 2021-04-20 12:30:09 +03:00
byte_order_generic_x86.h Fix all warnings given by UBSAN 2021-04-20 12:30:09 +03:00
byte_order_generic_x86_64.h typo fixed. HAVE_mi_uint8korr 2023-11-02 19:42:39 +11:00
CMakeLists.txt MDEV-34348: Consolidate cmp function declarations 2024-11-23 08:14:22 -07:00
decimal.h Added typedef decimal_digits_t (uint16) for number of digits in most 2021-05-19 22:27:27 +02:00
dur_prop.h
errmsg.h test cases for MySQL bugs 2022-01-21 16:02:34 +01:00
ft_global.h MDEV-31340 Remove MY_COLLATION_HANDLER::strcasecmp() 2024-04-18 15:22:10 +04:00
handler_ername.h MDEV-9101 forgotten symbolic error representation 2025-03-06 10:00:03 +01:00
handler_state.h
hash.h Merge 11.4 into 11.7 2024-12-02 17:51:17 +02:00
heap.h MDEV-35469 Heap tables are calling mallocs to often 2025-01-05 16:40:11 +02:00
ilist.h Merge 10.6 into 10.8 2023-02-10 13:43:53 +02:00
json_lib.h Merge branch '11.8' into 12.0 2025-05-22 09:22:55 +02:00
keycache.h Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
lf.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
little_endian.h Update FSF address 2019-05-11 19:25:02 +03:00
m_ctype.h Merge branch '11.8' into 12.0 2025-05-22 09:22:55 +02:00
m_string.h MDEV-31340 fixup: clang++-20 -Wdeprecated-literal-operator 2024-12-02 10:44:06 +02:00
ma_dyncol.h Merge 10.4 into 10.5 2023-01-03 17:08:42 +02:00
maria.h mhnsw: build indexes with the columns of exactly right size 2024-11-05 14:00:49 -08:00
mariadb_capi_rename.h more C API methods in the service_sql 2025-01-28 19:31:29 +01:00
my_alloc.h memroot improvement: fix savepoint support 2024-11-05 14:00:47 -08:00
my_alloca.h Merge branch '10.4' into 10.5 2023-04-24 12:43:47 +02:00
my_atomic.h MDEV-17441 fixup: Remove unused my_atomic long macros 2022-03-24 09:53:52 +02:00
my_atomic_wrapper.h Merge 10.5 into 10.6 2023-02-10 13:03:01 +02:00
my_attribute.h Get debug version to compile with gcc 7.5.0 2025-06-02 14:02:53 +03:00
my_base.h MDEV-35915 Implement Global temporary tables 2025-07-31 02:45:40 +02:00
my_bit.h cleanup: spaces, casts, comments 2024-11-05 14:00:47 -08:00
my_bitmap.h Merge 10.6 into 10.11 2024-03-28 09:16:57 +02:00
my_byteorder.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
my_check_opt.h Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
my_cmp.h MDEV-34348: Consolidate cmp function declarations 2024-11-23 08:14:22 -07:00
my_compare.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
my_compiler.h MDEV-33748 get rid of pthread_(get_/set_)specific, use thread_local 2024-06-21 13:46:41 +02:00
my_counter.h Apply clang-tidy to remove empty constructors / destructors 2023-02-09 16:09:08 +02:00
my_cpu.h Fix building with Clang and GCC on RISC-V 2025-03-21 18:28:36 +01:00
my_crypt.h Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
my_dbug.h Reënable ATTRIBUTE_FORMAT on DBUG_PRINT & t/eprint 2025-02-12 10:17:44 +01:00
my_decimal_limits.h header typos 2022-12-20 08:55:48 +11:00
my_default.h MDEV-22214 mariadbd.exe calls function mysqld.exe, and crashes 2020-04-10 19:05:26 +02:00
my_dir.h Merge 10.6 into 10.7 2023-01-04 14:52:25 +02:00
my_getopt.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
my_global.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
my_handler_errors.h Merge 11.4 into 11.7 2025-01-09 09:41:38 +02:00
my_libwrap.h Update FSF Address 2019-05-11 21:29:06 +03:00
my_list.h Update FSF Address 2019-05-11 21:29:06 +03:00
my_md5.h Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
my_minidump.h MDEV-11499 mysqltest, Windows : improve diagnostics if server fails to shutdown 2021-09-24 11:49:28 +02:00
my_net.h MDEV-25602 get rid of __WIN__ in favor of standard _WIN32 2021-06-06 13:21:03 +02:00
my_nosys.h Update FSF Address 2019-05-11 21:29:06 +03:00
my_pthread.h Merge branch '11.4' into 11.8 2025-06-18 07:43:24 +02:00
my_rdtsc.h MDEV-34815 SIGILL error when executing mariadbd compiled for RISC-V with Clang 2024-12-05 02:36:25 +11:00
my_rnd.h remove dead code 2022-07-31 14:54:37 +02:00
my_service_manager.h MDEV-32567 Remove thr_alarm from server codebase - socket activation fix 2023-11-23 11:52:38 +11:00
my_stack_alloc.h MDEV-36412 Concerns compilation issue on community edition for x86_64 with X32 ABI 2025-04-19 11:03:43 +03:00
my_stacktrace.h MDEV-25602 get rid of __WIN__ in favor of standard _WIN32 2021-06-06 13:21:03 +02:00
my_sys.h Merge branch '11.8' into 12.0 2025-05-22 09:22:55 +02:00
my_time.h Merge branch '11.4' into 11.8 2025-06-18 07:43:24 +02:00
my_tracker.h Changing all cost calculation to be given in milliseconds 2023-02-02 23:54:45 +03:00
my_tree.h Merge 10.2 into 10.3 2019-05-14 17:18:46 +03:00
my_uctype.h Update FSF Address 2019-05-11 21:29:06 +03:00
my_user.h Merge 10.2 into 10.3 2019-05-14 17:18:46 +03:00
my_valgrind.h Added VALGRIND_YIELD to be able to abort from busy loops 2025-04-28 12:59:39 +03:00
my_virtual_mem.h MDEV-36780: InnoDB buffer pool reserves all assigned memory 2025-05-13 12:27:42 +03:00
my_xml.h Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
myisam.h Merge 11.4 into 11.7 2024-12-02 17:51:17 +02:00
myisamchk.h MDEV-33751 Assertion `thd' failed in int temp_file_size_cb_func(tmp_file_tracking*, int) 2024-05-27 12:39:04 +02:00
myisammrg.h MDEV-31083 ASAN use-after-poison in myrg_attach_children 2023-05-23 09:16:36 +03:00
myisampack.h cleanup: remove unconditional #ifdef's 2024-11-05 14:00:47 -08:00
mysql.h fix error messages 2025-05-02 13:56:25 +02:00
mysql_com.h MDEV-33145 support for old-mode=OLD_FLUSH_STATUS 2024-05-27 12:39:03 +02:00
mysql_com_server.h Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
mysql_embed.h Merge branch '10.3' into 10.4 2019-05-19 20:55:37 +02:00
mysql_time.h Extends 64 bit windows to support timestamps up to year 2106. 2024-05-27 12:39:02 +02:00
mysql_version.h.in Merge 10.3 into 10.4 2020-10-29 13:38:38 +02:00
mysqld_default_groups.h Fixed that mariadb-# binaries reads their corresponding entry from my.cnf 2019-07-18 15:32:22 +03:00
mysys_err.h MDEV-9101 Limit size of created disk temporary files and tables 2024-05-27 12:39:04 +02:00
no_valgrind_without_big.inc MDEV-31893 Valgrind reports issues in main.join_cache_notasan 2023-08-10 20:57:42 +02:00
pack.h
password.h Merge 10.2 into 10.3 2019-05-14 17:18:46 +03:00
pfs_file_provider.h perfschema compilation, test and misc fixes 2020-03-10 19:24:23 +01:00
pfs_idle_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_memory_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_metadata_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_socket_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_stage_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_statement_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_table_provider.h P_S 5.7.28 2020-03-10 19:24:22 +01:00
pfs_thread_provider.h MDEV-32537 Name threads to improve debugging experience and diagnostics. 2024-07-09 13:17:20 +02:00
pfs_transaction_provider.h cleanup: pass trxid by value 2020-03-10 19:24:23 +01:00
probes_mysql.d.base Update FSF Address 2019-05-11 21:29:06 +03:00
probes_mysql.h Update FSF Address 2019-05-11 21:29:06 +03:00
probes_mysql_nodtrace.h.in
queues.h Merge 11.4 into 11.7 2024-12-02 17:51:17 +02:00
rijndael.h Update FSF Address 2019-05-11 21:29:06 +03:00
scope.h Merge branch '11.4' into 11.7 2025-02-06 16:46:36 +01:00
service_versions.h MDEV-34712 Add support to sha2 and pbkdf2 key derivation in file_key_management 2025-04-28 13:43:32 +10:00
source_revision.h.in
span.h Apply clang-tidy to remove empty constructors / destructors 2023-02-09 16:09:08 +02:00
sql_common.h Tag rest of my_vsnprintf users w/ ATTRIBUTE_FORMAT 2025-02-12 10:17:44 +01:00
ssl_compat.h Merge branch '10.6' into 10.9 2023-08-04 08:01:06 +02:00
sslopt-case.h client support for --ssl-fp and --ssl--fplist 2024-02-04 22:19:00 +01:00
sslopt-longopts.h MDEV-28908 Confusing documentation and help output for --ssl-verify-server-cert 2025-03-31 17:57:40 +02:00
sslopt-vars.h MDEV-32473 --disable-ssl doesn't disable it 2024-02-04 22:19:19 +01:00
t_ctype.h Update FSF Address 2019-05-11 21:29:06 +03:00
thr_lock.h MDEV-36425 Extend read_only to also block share locks and super user 2025-04-28 12:59:39 +03:00
thr_timer.h MDEV-16264 - prerequisite patch, periodic thr_timer 2019-11-15 16:50:22 +01:00
typelib.h cleanup: CREATE_TYPELIB_FOR() helper 2024-11-05 14:00:47 -08:00
violite.h MDEV-14091 Support password protected SSL key in server. 2025-04-19 14:04:10 +03:00
waiting_threads.h header typos 2022-12-20 08:55:48 +11:00
welcome_copyright_notice.h MDEV-30153 ad hoc client versions are confusing 2023-01-19 12:39:37 +01:00
wqueue.h Merge 10.2 into 10.3 2019-05-14 17:18:46 +03:00
wsrep.h Reduce compilation dependencies on wsrep_mysqld.h 2022-08-31 11:05:23 +03:00