The problem was that federated engine does not support comparable rowids
which was not taken into account by semijoin code.
Fixed by checking that we don't use semijoin with tables that does not
support comparable rowids.
Other things:
- Fixed some typos in the code comments
Works like vers_force but forces trx_id-based system-versioned tables
if the storage supports it (currently InnoDB-only). Otherwise creates
timestamp-based system-versioned table.
If the backup finished in the middle of a Aria bulk load insert,
which could happen with LOAD DATA INFILE, CREATE ... SELECT etc)
there was a chance that Aria recovery would fail on the backup.
Fixed by ensuring that bulk load operations for Aria are not allowed
under BACKUP LOCK.
I also changed so that the table TRN is updated just before truncate
which ensures that old redo's for the table are ignored.
I also enabled Aria redo for DDL's to be able to repeat REPAIR commands.
Without this change recovery would not work on repaired tables.
Notes:
- We take the backup lock protection at the end of bulk insert (as we
don't want to keep the lock over a very long running insert).
If mariadb-backup keeps the backup lock too long, this may fail with
a lock timeout. In this case the batch insert will fail and the table
will be truncated (set to it's original state).
Specifically:
Revert "MDEV-29664 Assertion `!n_mysql_tables_in_use' failed in innobase_close_connection"
This reverts commit ba875e9396.
Revert "MDEV-29620 Assertion `next_insert_id == 0' failed in handler::ha_external_lock"
This reverts commit aa08a7442a.
Revert "MDEV-29628 Memory leak after CREATE OR REPLACE with foreign key"
This reverts commit c579d66ba6.
Revert "MDEV-29609 create_not_windows test fails with different result"
This reverts commit cb583b2f1b.
Revert "MDEV-29544 SIGSEGV in HA_CREATE_INFO::finalize_locked_tables"
This reverts commit dcd66c3814.
Revert "MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name"
This reverts commit cf6c517632.
Revert "MDEV-28933 Moved RENAME_CONSTRAINT_IDS to include/sql_funcs.h"
This reverts commit f1e1c1335b.
Revert "MDEV-28956 Locking is broken if CREATE OR REPLACE fails under LOCK TABLES"
This reverts commit a228ec80e3.
Revert "MDEV-25292 gcol.gcol_bugfixes --ps fix"
This reverts commit 24fff8267d.
Revert "MDEV-25292 Disable atomic replace for slave-generated or-replace"
This reverts commit 2af15914cb.
Revert "MDEV-25292 backup_log improved"
This reverts commit 34398a20b5.
Revert "MDEV-25292 Atomic CREATE OR REPLACE TABLE"
This reverts commit 93c8252f02.
Revert "MDEV-25292 Table_name class for (db, table_name, alias)"
This reverts commit d145dda9c7.
Revert "MDEV-25292 ha_table_exists() cleanup and improvement"
This reverts commit 409b8a86de.
Revert "MDEV-25292 Cleanups"
This reverts commit 595dad83ad.
Revert "MDEV-25292 Refactoring: moved select_field_count into Alter_info."
This reverts commit f02af1d229.
When a range rowid filter was used with an index ref access the cost of
accessing the index entries for the records rejected by the filter was not
taken into account. For a ref access by an index with big average number
of records per key this led to poor execution plans if selectivity of the
used filter was high.
The patch resolves this problem. It also introduces a minor optimization
that skips look-ups into a filter that turns out to be empty.
With this patch the output of ANALYZE stmt reports the number of look-ups
into used rowid filters.
The patch also back-ports from 10.5 the code that properly sets the field
TABLE::file::table for opened temporary tables.
The test cases that were supposed to use rowid filters have been adjusted
in order to use similar execution plans after this fix.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
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>
TABLEOP_HOOKS is a strange interface: proxy interface calls virtual
interface. Since it is used only for select_create::prepare() such
complexity is overwhelming.
There is a need in MDEV-25292 to have both C_ALTER_TABLE and
select_field_count in one call. Semantically creation mode and field
count are two different things. Making creation mode negative
constants and field count positive variable into one parameter seems
to be a lazy hack for not making the second parameter.
select_count does not make sense without alter_info->create_list, so
the natural way is to hold it in Alter_info too. select_count is now
stored in member select_field_count.
Also fixes
MDEV-27782 Wrong columns when using table level `CHARACTER SET utf8mb4 COLLATE DEFAULT`
MDEV-28644 Unexpected error on ALTER TABLE t1 CONVERT TO CHARACTER SET utf8mb3, DEFAULT CHARACTER SET utf8mb4
that is not in binlog.
Post-crash recovery of --rpl-semi-sync-slave-enabled server
failed to recognize a transaction in-doubt that needed rolled back.
A prepared-but-not-in-binlog transaction gets committed instead
to possibly create inconsistency with a master (e.g the way it was observed
in the bug report).
The semisync recovery is corrected now with initializing binlog coordinates
of any transaction in-doubt to the maximum offset which is
unreachable.
In effect when a prepared transaction that is not found in binlog
it will be decided to rollback because it's guaranteed to reside
in a truncated tail area of binlog.
Mtr tests are reinforced to cover the described scenario.
:: Syntax change ::
Keyword AUTO enables history partition auto-creation.
Examples:
CREATE TABLE t1 (x int) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 HOUR AUTO;
CREATE TABLE t1 (x int) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 MONTH
STARTS '2021-01-01 00:00:00' AUTO PARTITIONS 12;
CREATE TABLE t1 (x int) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME LIMIT 1000 AUTO;
Or with explicit partitions:
CREATE TABLE t1 (x int) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 HOUR AUTO
(PARTITION p0 HISTORY, PARTITION pn CURRENT);
To disable or enable auto-creation one can use ALTER TABLE by adding
or removing AUTO from partitioning specification:
CREATE TABLE t1 (x int) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 HOUR AUTO;
# Disables auto-creation:
ALTER TABLE t1 PARTITION BY SYSTEM_TIME INTERVAL 1 HOUR;
# Enables auto-creation:
ALTER TABLE t1 PARTITION BY SYSTEM_TIME INTERVAL 1 HOUR AUTO;
If the rest of partitioning specification is identical to CREATE TABLE
no repartitioning will be done (for details see MDEV-27328).
:: Description ::
Before executing history-generating DML command (see the list of commands below)
add N history partitions, so that N would be sufficient for potentially
generated history. N > 1 may be required when history partitions are switched
by INTERVAL and current_timestamp is N times further than the interval
boundary of the last history partition.
If the last history partition equals or exceeds LIMIT records then new history
partition is created and selected as the working partition. According to
MDEV-28411 partitions cannot be switched (or created) while the command is
running. Thus LIMIT does not carry strict limitation and the history partition
size must be planned as LIMIT value plus average number of history one DML
command can generate.
Auto-creation is implemented by synchronous fast_alter_partition_table() call
from the thread of the executed DML command before the command itself is run
(by the fallback and retry mechanism similar to Discovery feature,
see Open_table_context).
The name for newly added partitions are generated like default partition names
with extension of MDEV-22155 (which avoids name clashes by extending assignment
counter to next free-enough gap).
These DML commands can trigger auto-creation:
DELETE (including multitable DELETE, excluding DELETE HISTORY)
UPDATE (including multitable UPDATE)
REPLACE (including REPLACE .. SELECT)
INSERT .. ON DUPLICATE KEY UPDATE (including INSERT .. SELECT .. ODKU)
LOAD DATA .. REPLACE
:: Bug fixes ::
MDEV-23642 Locking timeout caused by auto-creation affects original DML
The reasons for this are:
- Do not disrupt main business process (the history is auxiliary service);
- Consequences are non-fatal (history is not lost, but comes into wrong
partition; fixed by partitioning rebuild);
- There is more freedom for application to fail in this case or not: it may
read warning info and find corresponding error number.
- While non-failing command is easy to handle by an application and fail it,
the opposite is hard to handle: there is no automatic actions to fix
failed command and retry, DBA intervention is required and until then
application is non-functioning.
MDEV-23639 Auto-create does not work under LOCK TABLES or inside triggers
Don't do tdc_remove_table() for OT_ADD_HISTORY_PARTITION because it is
not possible in locked tables mode.
LTM_LOCK_TABLES mode (and LTM_PRELOCKED_UNDER_LOCK_TABLES) works out
of the box as fast_alter_partition_table() can reopen tables via
locked_tables_list.
In LTM_PRELOCKED we reopen and relock table manually.
:: More fixes ::
* some_table_marked_for_reopen flag fix
some_table_marked_for_reopen affets only reopen of
m_locked_tables. I.e. Locked_tables_list::reopen_tables() reopens only
tables from m_locked_tables.
* Unused can_recover_from_failed_open() condition
Is recover_from_failed_open() can be really used after
open_and_process_routine()?
:: Reviewed by ::
Sergei Golubchik <serg@mariadb.org>
EXPLAIN FOR CONNECTION is a MySQL-compatible syntax for SHOW EXPLAIN.
This commit also adds support for FORMAT=JSON to SHOW EXPLAIN,
so the possible options to get JSON-formatted output are:
- SHOW EXPLAIN FORMAT=JSON FOR $con
- EXPLAIN FORMAT=JSON FOR CONNECTION $con
We will remove the parameter innodb_disallow_writes because it is badly
designed and implemented. The parameter was never allowed at startup.
It was only internally used by Galera snapshot transfer.
If a user executed
SET GLOBAL innodb_disallow_writes=ON;
the server could hang even on subsequent read operations.
During Galera snapshot transfer, we will block writes
to implement an rsync friendly snapshot, as follows:
sst_flush_tables() will acquire a global lock by executing
FLUSH TABLES WITH READ LOCK, which will block any writes
at the high level.
sst_disable_innodb_writes(), invoked via ha_disable_internal_writes(true),
will suspend or disable InnoDB background tasks or threads that could
initiate writes. As part of this, log_make_checkpoint() will be invoked
to ensure that anything in the InnoDB buf_pool.flush_list will be written
to the data files. This has the nice side effect that the Galera joiner
will avoid crash recovery.
The changes to sql/wsrep.cc and to the tests are based on a prototype
that was developed by Jan Lindström.
Reviewed by: Jan Lindström
