Specifically:
Revert "MDEV-29664 Assertion `!n_mysql_tables_in_use' failed in innobase_close_connection"
This reverts commit ba875e939619baefb08936863a889830f595e426.
Revert "MDEV-29620 Assertion `next_insert_id == 0' failed in handler::ha_external_lock"
This reverts commit aa08a7442a5141750de96353132c7799e10c9302.
Revert "MDEV-29628 Memory leak after CREATE OR REPLACE with foreign key"
This reverts commit c579d66ba689c8a20a951de5e6be2e1bc255ba7f.
Revert "MDEV-29609 create_not_windows test fails with different result"
This reverts commit cb583b2f1bf1c910e82c7caee4a53e0f3ff954ba.
Revert "MDEV-29544 SIGSEGV in HA_CREATE_INFO::finalize_locked_tables"
This reverts commit dcd66c3814991e686615eac2e65d01a7fa80cb66.
Revert "MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name"
This reverts commit cf6c5176328c8fbfadac80f337ef285732cc8d06.
Revert "MDEV-28933 Moved RENAME_CONSTRAINT_IDS to include/sql_funcs.h"
This reverts commit f1e1c1335b506905244502ee8584736a17a6ecd0.
Revert "MDEV-28956 Locking is broken if CREATE OR REPLACE fails under LOCK TABLES"
This reverts commit a228ec80e30cae59c2057b786fd3559171ce794f.
Revert "MDEV-25292 gcol.gcol_bugfixes --ps fix"
This reverts commit 24fff8267d0722b20ca780cf144ce27560df1394.
Revert "MDEV-25292 Disable atomic replace for slave-generated or-replace"
This reverts commit 2af15914cb3ae204d3b413995a96c7722ad60d93.
Revert "MDEV-25292 backup_log improved"
This reverts commit 34398a20b5829f0508c78bc8f765f7bef6e0ad48.
Revert "MDEV-25292 Atomic CREATE OR REPLACE TABLE"
This reverts commit 93c8252f02faa8ad8dc5f005e52f1990c29d4a0d.
Revert "MDEV-25292 Table_name class for (db, table_name, alias)"
This reverts commit d145dda9c7b6db394edf7150cc255343a4a7b116.
Revert "MDEV-25292 ha_table_exists() cleanup and improvement"
This reverts commit 409b8a86de45efc96377c618a99cff1301523150.
Revert "MDEV-25292 Cleanups"
This reverts commit 595dad83ad3c23879c59deec1173ea16b47871ed.
Revert "MDEV-25292 Refactoring: moved select_field_count into Alter_info."
This reverts commit f02af1d2295f108d96671b5a4f731ec998002dd5.
The ALTER related code cannot do at the same time both:
- modify partitions
- change column data types
Explicit changing of a column data type together with a partition change is
prohibited by the parter, so this is not allowed and returns a syntax error:
ALTER TABLE t MODIFY ts BIGINT, DROP PARTITION p1;
This fix additionally disables implicit data type upgrade
(e.g. from "MariaDB 5.3 TIME" to "MySQL 5.6 TIME", or the other way
around according to the current mysql56_temporal_format) in case of
an ALTER modifying partitions, e.g.:
ALTER TABLE t DROP PARTITION p1;
In such commands now only the partition change happens, while
the data types stay unchanged.
One can additionally run:
ALTER TABLE t FORCE;
either before or after the ALTER modifying partitions to
upgrade data types according to mysql56_temporal_format.
10.5 part: test cases and comments.
The code is in the merge commit 74fe1c44aa1
When f.ex. table is partitioned by HASH(a) and we rename column `a' to
`b' partitioning filter stays unchanged: HASH(a). That's the wrong
behavior.
The patch updates partitioning filter in accordance to the new columns
names. That includes partition/subpartition expression and
partition/subpartition field list.
When f.ex. table is partitioned by HASH(a) and we rename column `a' to
`b' partitioning filter stays unchanged: HASH(a). That's the wrong
behavior.
The patch updates partitioning filter in accordance to the new columns
names. That includes partition/subpartition expression and
partition/subpartition field list.
make_tmp_name() creates temporary name with prefix containing PID and
TID. This prefix influences max length of the rest of the name (the
whole name is limited by NAME_LEN). During the test run PID and TID
can change. PID increases when the server restarts. TID is incremented
with the new connections (generated by next_thread_id(), is not the
posix thread ID).
During the test run PID can increase max 2 decimal positions: from
tens to thousands this requires ~900 restarts. TID depends on
connection count, but for test we assume it will not trespass 100000
connections which is 5 decimal positions. So it should be enough to
reserve 7 characters for PID and TID increment.
The patch reserves more: it reserves 12 characters for 7-decimal PID
and 5-decimal TID plus 4 chars of additional reserve (for future
prefix changes) and assumes minimal legth of the prefix is 30 bytes:
#sql-backup-PID-TID-
#sql-create-PID-TID-
4-6-PID-TID- is 10 + 4 + PID + TID, so PID + TID is 16 chars (7 + 5 + 4).
Usually when we get into finalize_locked_tables() with error
m_locked_tables_count was not decremented. m_locked_tables_count is
decremented when we drop the original table and if we failed that
m_locked_tables_count is expected intact.
The bug comes from the fact that finalize_atomic_replace() violates
the above contract. It does HA_EXTRA_PREPARE_FOR_DROP and decrements
m_locked_tables_count. Then it tries rename_table_and_triggers() and
fails. With decremented m_locked_tables_count reopen_tables() does
nothing and we don't get new value for pos_in_locked_tables->table.
The test case demonstrates ER_ERROR_ON_RENAME where non-atomic CREATE
OR REPLACE would not fail. The original RENAME TABLE fails under such
broken environment, so nothing is wrong with atomic CREATE OR REPLACE
failing there too.
There are separate flags DBUG_OFF for disabling the DBUG facility
and ENABLED_DEBUG_SYNC for enabling the DEBUG_SYNC facility.
Let us allow debug builds without DEBUG_SYNC.
Note: For CMAKE_BUILD_TYPE=Debug, CMakeLists.txt will continue to
define ENABLED_DEBUG_SYNC.
add_back_last_deleted_lock() was called when the lock was never
removed. Lock is removed in finalize_atomic_replace() in
close_all_tables_for_name(). finalize_atomic_replace() is done only
for successful operation.
In non-atomic codepath it drops the table first, if anything fails
later we don't need to return back the lock since there is no table
now. So the fix is required as well.
Atomic CREATE OR REPLACE allows to keep an old table intact if the
command fails or during the crash. That is done through creating
a table with a temporary name and filling it with the data
(for CREATE OR REPLACE .. SELECT), then renaming the original table
to another temporary (backup) name and renaming the replacement table
to original table. The backup table is kept until the last chance of
failure and if that happens, the replacement table is thrown off and
backup recovered. When the command is complete and logged the backup
table is deleted.
Atomic replace algorithm
Two DDL chains are used for CREATE OR REPLACE:
ddl_log_state_create (C) and ddl_log_state_rm (D).
1. (C) Log CREATE_TABLE_ACTION of TMP table (drops TMP table);
2. Create new table as TMP;
3. Do everything with TMP (like insert data);
finalize_atomic_replace():
4. Link chains: (D) is executed only if (C) is closed;
5. (D) Log DROP_ACTION of BACKUP;
6. (C) Log RENAME_TABLE_ACTION from ORIG to BACKUP (replays BACKUP -> ORIG);
7. Rename ORIG to BACKUP;
8. (C) Log CREATE_TABLE_ACTION of ORIG (drops ORIG);
9. Rename TMP to ORIG;
finalize_ddl() in case of success:
10. Close (C);
11. Replay (D): BACKUP is dropped.
finalize_ddl() in case of error:
10. Close (D);
11. Replay (C):
1) ORIG is dropped (only after finalize_atomic_replace());
2) BACKUP renamed to ORIG (only after finalize_atomic_replace());
3) drop TMP.
If crash happens (C) or (D) is replayed in reverse order. (C) is
replayed if crash happens before it is closed, otherwise (D) is
replayed.
Temporary table for CREATE OR REPLACE
Before dropping "old" table, CREATE OR REPLACE creates "tmp" table.
ddl_log_state_create holds the drop of the "tmp" table. When
everything is OK (data is inserted, "tmp" is ready) ddl_log_state_rm
is written to replace "old" with "tmp". Until ddl_log_state_create
is closed ddl_log_state_rm is not executed.
After the binlogging is done ddl_log_state_create is closed. At that
point ddl_log_state_rm is executed and "tmp" is replaced with
"old". That is: final rename is done by the DDL log.
With that important role of DDL log for CREATE OR REPLACE operation
replay of ddl_log_state_rm must fail at the first hit error and
print the error message if possible. F.ex. foreign key error is
discovered at this phase: InnoDB rejects to drop the "old" table and
returns corresponding foreign key error code.
Additional notes
- CREATE TABLE without REPLACE is not affected by this commit.
- Engines having HTON_EXPENSIVE_RENAME flag set are not affected by
this commit.
- CREATE TABLE .. SELECT XID usage is fixed and now there is no need
to log DROP TABLE via DDL_CREATE_TABLE_PHASE_LOG (see comments in
do_postlock()). XID is now correctly updated so it disables
DDL_LOG_DROP_TABLE_ACTION. Note that binary log is flushed at the
final stage when the table is ready. So if we have XID in the
binary log we don't need to drop the table.
- Three variations of CREATE OR REPLACE handled:
1. CREATE OR REPLACE TABLE t1 (..);
2. CREATE OR REPLACE TABLE t1 LIKE t2;
3. CREATE OR REPLACE TABLE t1 SELECT ..;
- Test case uses 6 combinations for engines (aria, aria_notrans,
myisam, ib, lock_tables, expensive_rename) and 2 combinations for
binlog types (row, stmt). Combinations help to check differences
between the results. Error failures are tested for the above three
variations.
- expensive_rename tests CREATE OR REPLACE without atomic
replace. The effect should be the same as with the old behaviour
before this commit.
- Triggers mechanism is unaffected by this change. This is tested in
create_replace.test.
- LOCK TABLES is affected. Lock restoration must be done after "rm"
chain is replayed.
- Moved ddl_log_complete() from send_eof() to finalize_ddl(). This
checkpoint was not executed before for normal CREATE TABLE but is
executed now.
- CREATE TABLE will now rollback also if writing to the binary
logging failed. See rpl_gtid_strict.test
Rename and drop via DDL log
We replay ddl_log_state_rm to drop the old table and rename the
temporary table. In that case we must throw the correct error
message if ddl_log_revert() fails (f.ex. on FK error).
If table is deleted earlier and not via DDL log and the crash
happened, the create chain is not closed. Linked drop chain is not
executed and the new table is not installed. But the old table is
already deleted.
ddl_log.cc changes
Now we can place action before DDL_LOG_DROP_INIT_ACTION and it will
be replayed after DDL_LOG_DROP_TABLE_ACTION.
report_error parameter for ddl_log_revert() allows to fail at first
error and print the error message if possible.
ddl_log_execute_action() now can print error message.
Since we now can handle errors from ddl_log_execute_action() (in
case of non-recovery execution) unconditional setting "error= TRUE"
is wrong (it was wrong anyway because it was overwritten at the end
of the function).
On XID usage
Like with all other atomic DDL operations XID is used to avoid
inconsistency between master and slave in the case of a crash after
binary log is written and before ddl_log_state_create is closed. On
recovery XIDs are taken from binary log and corresponding DDL log
events get disabled. That is done by
ddl_log_close_binlogged_events().
On linking two chains together
Chains are executed in the ascending order of entry_pos of execute
entries. But entry_pos assignment order is undefined: it may assign
bigger number for the first chain and then smaller number for the
second chain. So the execution order in that case will be reverse:
second chain will be executed first.
To avoid that we link one chain to another. While the base chain
(ddl_log_state_create) is active the secondary chain
(ddl_log_state_rm) is not executed. That is: only one chain can be
executed in two linked chains.
The interface ddl_log_link_chains() was done in "MDEV-22166
ddl_log_write_execute_entry() extension".
More on CREATE OR REPLACE .. SELECT
We use create_and_open_tmp_table() like in ALTER TABLE to create
temporary TABLE object (tmp_table is (NON_)TRANSACTIONAL_TMP_TABLE).
After we created such TABLE object we use create_info->tmp_table()
instead of table->s->tmp_table when we need to check for
parser-requested tmp-table.
External locking is required for temporary table created by
create_and_open_tmp_table(). F.ex. that disables logging for Aria
transactional tables and without that (when no mysql_lock_tables()
is done) it cannot work correctly.
For making external lock the patch requires Aria table to work in
non-transactional mode. That is usually done by
ha_enable_transaction(false). But we cannot disable transaction
completely because: 1. binlog rollback removes pending row events
(binlog_remove_pending_rows_event()). The row events are added
during CREATE .. SELECT data insertion phase. 2. replication slave
highly depends on transaction and cannot work without it.
So we put temporary Aria table into non-transactional mode with
"thd->transaction->on hack". See comment for on_save variable.
Note that Aria table has internal_table mode. But we cannot use it
because:
if (!internal_table)
{
mysql_mutex_lock(&THR_LOCK_myisam);
old_info= test_if_reopen(name_buff);
}
For internal_table test_if_reopen() is not called and we get a new
MARIA_SHARE for each file handler. In that case duplicate errors are
missed because insert and lookup in CREATE .. SELECT is done via two
different handlers (see create_lookup_handler()).
For temporary table before dropping TABLE_SHARE by
drop_temporary_table() we must do ha_reset(). ha_reset() releases
storage share. Without that the share is kept and the second CREATE
OR REPLACE .. SELECT fails with:
HA_ERR_TABLE_EXIST (156): MyISAM table '#sql-create-b5377-4-t2' is
in use (most likely by a MERGE table). Try FLUSH TABLES.
HA_EXTRA_PREPARE_FOR_DROP also removes MYISAM_SHARE, but that is
not needed as ha_reset() does the job.
ha_reset() is usually done by
mark_tmp_table_as_free_for_reuse(). But we don't need that mechanism
for our temporary table.
Atomic_info in HA_CREATE_INFO
Many functions in CREATE TABLE pass the same parameters. These
parameters are part of table creation info and should be in
HA_CREATE_INFO (or whatever). Passing parameters via single
structure is much easier for adding new data and
refactoring.
InnoDB changes (revised by Marko Mäkelä)
row_rename_table_for_mysql(): Specify the treatment of FOREIGN KEY
constraints in a 4-valued enum parameter. In cases where FOREIGN KEY
constraints cannot exist (partitioned tables, or internal tables of
FULLTEXT INDEX), we can use the mode RENAME_IGNORE_FK.
The mod RENAME_REBUILD is for any DDL operation that rebuilds the
table inside InnoDB, such as TRUNCATE and native ALTER TABLE
(or OPTIMIZE TABLE). The mode RENAME_ALTER_COPY is used solely
during non-native ALTER TABLE in ha_innobase::rename_table().
Normal ha_innobase::rename_table() will use the mode RENAME_FK.
CREATE OR REPLACE will rename the old table (if one exists) along
with its FOREIGN KEY constraints into a temporary name. The replacement
table will be initially created with another temporary name.
Unlike in ALTER TABLE, all FOREIGN KEY constraints must be renamed
and not inherited as part of these operations, using the mode RENAME_FK.
dict_get_referenced_table(): Let the callers convert names when needed.
create_table_info_t::create_foreign_keys(): CREATE OR REPLACE creates
the replacement table with a temporary name table, so for
self-references foreign->referenced_table will be a table with
temporary name and charset conversion must be skipped for it.
Reviewed by:
Michael Widenius <monty@mariadb.org>
