- In ha_innobase::prepare_inplace_alter_table(), InnoDB should
check whether the table is empty. If the table is empty then
server should avoid downgrading the MDL after prepare phase.
It is more like instant alter, does change only in dicationary
and metadata.
- Changed few debug test case to make non-empty DDL table
Drop and add same key is considered rename (look ALTER_RENAME_INDEX in
fill_alter_inplace_info()). But in this case order of keys may be
changed, because mysql_prepare_alter_table() yet does not know about
rename and treats 2 operations: drop and add.
In that case we disable inplace algorithm for such engines as Memory,
MyISAM and Aria with ALTER_INDEX_ORDER flag. These engines have no
specialized check_if_supported_inplace_alter() and default
handler::check_if_supported_inplace_alter() sees an unknown flag and
returns HA_ALTER_INPLACE_NOT_SUPPORTED.
ha_innobase::check_if_supported_inplace_alter() works differently and
inplace is not disabled (with the help of modified
INNOBASE_INPLACE_IGNORE). add_drop_v_cols fork was also tweaked as it
wrongly failed with MSG_UNSUPPORTED_ALTER_ONLINE_ON_VIRTUAL_COLUMN
when it seen ALTER_INDEX_ORDER.
No-op operation must be still no-op no matter of ALTER_INDEX_ORDER
presence, so we tweek its condition as well.
mysql_prepare_create_table() does my_qsort(sort_keys) on key
info. This sorting is indeterministic: a table is created with one
order and inplace alter may overwrite frm with another order. Since
inplace alter does nothing about key info for MyISAM/Aria storage
engines this results in discrepancy between frm and storage engine key
definitions.
The fix avoids the sorting of keys when no new keys added by ALTER
(and this is ok for MyISAM/Aria since it cannot add new keys inplace).
There is a case when implicit primary key may be changed when removing
NOT NULL from the part of unique key. In that case we update
modified_primary_key which is then used to not skip key sorting.
According to is_candidate_key() there is no other cases when primary
key may be changed implicitly.
Notes:
mi_keydef_write()/mi_keyseg_write() are used only in mi_create(). They
should be used in ha_inplace_alter_table() as well.
Aria corruption detection is unimplemented: maria_check_definition()
is never used!
MySQL 8.0 has this bug as well as of 8.0.26.
There is a case when implicit primary key may be changed when removing
NOT NULL from the part of unique key. In that case we update
modified_primary_key which is then used to not skip key sorting.
According to is_candidate_key() there is no other cases when primary
kay may be changed implicitly.
mysql_prepare_create_table() does my_qsort(sort_keys) on key
info. This sorting is indeterministic: a table is created with one
order and inplace alter may overwrite frm with another order. Since
inplace alter does nothing about key info for MyISAM/Aria storage
engines this results in discrepancy between frm and storage engine key
definitions.
The fix avoids the sorting of keys when no new keys added by ALTER
(and this is ok for MyISAM/Aria since it cannot add new keys inplace).
Notes:
mi_keydef_write()/mi_keyseg_write() are used only in mi_create(). They
should be used in ha_inplace_alter_table() as well.
Aria corruption detection is unimplemented: maria_check_definition()
is never used!
MySQL 8.0 has this bug as well as of 8.0.26.
This breaks main.long_unique in 10.4. The new result is correct and
should be applied as it just different (original) order of keys.
mysql_write_frm(): Correctly enclose code inside
#ifdef WITH_PARTITION_STORAGE_ENGINE
so that cmake -DPLUGIN_PARTITION=NO builds can succeed.
This was broken in
commit b7bba721ee.
Syntax for CONVERT TABLE
ALTER TABLE tbl_name CONVERT TABLE tbl_name TO PARTITION partition_name partition_spec
Examples:
ALTER TABLE t1 CONVERT TABLE tp2 TO PARTITION p2 VALUES LESS THAN MAX_VALUE();
New ALTER_PARTITION_CONVERT_IN command for
fast_alter_partition_table() is done in alter_partition_convert_in()
function which basically does ha_rename_table().
Table structure and data check is basically the same as in EXCHANGE
PARTITION command. And these are done by
compare_table_with_partition() and check_table_data().
Atomic DDL is done by the scheme from MDEV-22166 (see the
corresponding commit message). The only differnce is that it also has
to drop source table frm and that is done by WFRM_DROP_CONVERTED_FROM.
Initial patch was done by Dmitry Shulga <dmitry.shulga@mariadb.com>
Syntax for CONVERT keyword
ALTER TABLE tbl_name
[alter_option [, alter_option] ...] |
[partition_options]
partition_option: {
...
| CONVERT PARTITION partition_name TO TABLE tbl_name
}
Examples:
ALTER TABLE t1 CONVERT PARTITION p2 TO TABLE tp2;
New ALTER_PARTITION_CONVERT_OUT command for
fast_alter_partition_table() is done in alter_partition_convert_out()
function which basically does ha_rename_table().
Partition to extract is marked with the same flag as dropped
partition: PART_TO_BE_DROPPED. Note that we cannot have multiple
partitioning commands in one ALTER.
For DDL logging basically the principle is the same as for other
fast_alter_partition_table() commands. The only difference is that it
integrates late Atomic DDL functions and introduces additional phase
of WFRM_BACKUP_ORIGINAL. That is required for binlog consistency
because otherwise we could not revert back after WFRM_INSTALL_SHADOW
is done. And before DDL log is complete if we crash or fail the
altered table will be already new but binlog will miss that ALTER
command. Note that this is different from all other atomic DDL in that
it rolls back until the ddl_log_complete() is done even if everything
was done fully before the crash.
Test cases added to:
parts.alter_table \
parts.partition_debug \
versioning.partition \
atomic.alter_partition
Dead code cleanup:
part_info->num_parts usage was wrong and working incorrectly in
mysql_drop_partitions() because num_parts is already updated in
prep_alter_part_table(). We don't have to update part_info->partitions
because part_info is destroyed at alter_partition_lock_handling().
Cleanups:
- DBUG_EVALUATE_IF() macro replaced by shorter form DBUG_IF();
- Typo in ER_KEY_COLUMN_DOES_NOT_EXITS.
Refactorings:
- Splitted write_log_replace_delete_frm() into write_log_delete_frm()
and write_log_replace_frm();
- partition_info via DDL_LOG_STATE;
- set_part_info_exec_log_entry() removed.
DBUG_EVALUATE removed
DBUG_EVALUTATE was only added for consistency together with
DBUG_EVALUATE_IF. It is not used anywhere in the code.
DBUG_SUICIDE() fix on release build
On release DBUG_SUICIDE() was statement. It was wrong as
DBUG_SUICIDE() is used in expression context.
Assertion `!pk->has_virtual()' failed in dict_index_build_internal_clust
while creating PRIMARY key longer than possible to store in the page.
This happened because the key was wrongly deduced as Long UNIQUE supported,
however PRIMARY KEY cannot be of that type. The main reason is that
only 8 bytes are used to store the hash, see HA_HASH_FIELD_LENGTH.
This is also why HA_NOSAME flag is removed (and caused the assertion in
turn) in open_table_from_share:
if (key_info->algorithm == HA_KEY_ALG_LONG_HASH)
{
key_part_end++;
key_info->flags&= ~HA_NOSAME;
}
To make it unique, the additional check is done by
check_duplicate_long_entries call from ha_write_row, and similar one from
ha_update_row.
PRIMARY key is already forbidden, which is checked by the first test in
main.long_unique, however is_hash_field_needed was wrongly deduced to true
in mysql_prepare_create_table in this particular case.
FIX:
* Improve the check for Key::PRIMARY type
* Simplify is_hash_field_needed deduction for a more neat reading
- There should be no substitution if engine exists, only when doesn't
exist
- Handling of an error when sys_var `default_tmp_storage_engine` is
assigned to unsupported engine.
- rocksdb doesn't support embedded server ebfc4e6ad0 so is excluded
Closes PR #774
Reviewed by: serg@mariadb.comvicentiu@mariadb.org
We cannot revert the ALTER, so anything happening after
the point of no return should not be treated as an error. A
very unfortunate condition that a user needs to be warned about - yes,
but we cannot say "ALTER TABLE has failed" if the table was successfully
altered.
A table rebuild that would truncate the default value of a
DATE column is expected to issue data truncation warnings.
But, these warnings are not being issued if the ADD COLUMN
is being executed with ALGORITHM=INSTANT. InnoDB sets the
warning of the field while assigning the default value
of the field during check_if_supported_inplace_alter().
Withing this task the following changes were made:
- Added sending of metadata info in prepare phase for the admin related
command (check table, checksum table, repair, optimize, analyze).
- Refactored implmentation of HELP command to support its execution in
PS mode
- Added support for execution of LOAD INTO and XA- related statements
in PS mode
- Modified mysqltest.cc to run statements in PS mode unconditionally
in case the option --ps-protocol is set. Formerly, only those statements
were executed using PS protocol that matched the hard-coded regular expression
- Fixed the following issues:
The statement
explain select (select 2)
executed in regular and PS mode produces different results:
MariaDB [test]> prepare stmt from "explain select (select 2)";
Query OK, 0 rows affected (0,000 sec)
Statement prepared
MariaDB [test]> execute stmt;
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| 1 | PRIMARY | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
| 2 | SUBQUERY | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
2 rows in set (0,000 sec)
MariaDB [test]> explain select (select 2);
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
| 1 | SIMPLE | NULL | NULL | NULL | NULL | NULL | NULL | NULL | No tables used |
+------+-------------+-------+------+---------------+------+---------+------+------+----------------+
1 row in set, 1 warning (0,000 sec)
In case the statement
CREATE TABLE t1 SELECT * FROM (SELECT 1 AS a, (SELECT a+0)) a
is run in PS mode it fails with the error
ERROR 1054 (42S22): Unknown column 'a' in 'field list'.
- Uniform handling of read-only variables both in case the SET var=val
statement is executed as regular or prepared statememt.
- Fixed assertion firing on handling LOAD DATA statement for temporary tables
- Relaxed assert condition in the function lex_end_stage1() by adding
the commands SQLCOM_ALTER_EVENT, SQLCOM_CREATE_PACKAGE,
SQLCOM_CREATE_PACKAGE_BODY to a list of supported command
- Removed raising of the error ER_UNSUPPORTED_PS in the function
check_prepared_statement() for the ALTER VIEW command
- Added initialization of the data memember st_select_lex_unit::last_procedure
(assign NULL value) in the constructor
Without this change the test case main.ctype_utf8 fails with the following
report in case it is run with the optoin --ps-protocol.
mysqltest: At line 2278: query 'VALUES (_latin1 0xDF) UNION VALUES(_utf8'a' COLLATE utf8_bin)' failed: 2013: Lost connection
- The following bug reports were fixed:
MDEV-24460: Multiple rows result set returned from stored
routine over prepared statement binary protocol is
handled incorrectly
CONC-519: mariadb client library doesn't handle server_status and
warnign_count fields received in the packet
COM_STMT_EXECUTE_RESPONSE.
Reasons for these bug reports have the same nature and caused by
missing loop iteration on results sent by server in response to
COM_STMT_EXECUTE packet.
Enclosing of statements for processing of COM_STMT_EXECUTE response
in the construct like
do
{
...
} while (!mysql_stmt_next_result());
fixes the above mentioned bug reports.
In commit 1c5ae99194 (MDEV-25666)
we had changed Mariabackup so that it would no longer skip files
whose names start with #sql. This turned out to be wrong.
Because operations on such named files are not protected by any
locks in the server, it is not safe to copy them.
Not copying the files may make the InnoDB data dictionary
inconsistent with the file system. So, we must do something
in InnoDB to adjust for that.
If InnoDB is being started up without the redo log (ib_logfile0)
or with a zero-length log file, we will assume that the server
was restored from a backup, and adjust things as follows:
dict_check_sys_tables(), fil_ibd_open(): Do not complain about
missing #sql files if they would be dropped a little later.
dict_stats_update_if_needed(): Never add #sql tables to
the recomputing queue. This avoids a potential race condition when
dropping the garbage tables.
drop_garbage_tables_after_restore(): Try to drop any garbage tables.
innodb_ddl_recovery_done(): Invoke drop_garbage_tables_after_restore()
if srv_start_after_restore (a new flag) was set and we are not in
read-only mode (innodb_read_only=ON or innodb_force_recovery>3).
The tests and dbug_mariabackup_event() instrumentation
were developed by Vladislav Vaintroub, who also reviewed this.
1. work around MDEV-25912 to not apply assert
at wsrep running time;
2. handle wsrep mode of the server recovery
3. convert hton calls to static binlog_commit ones.
4. satisfy MSAN complain on uninitialized std::pair
- InnoDB fails to check DB_COMPUTE_VALUE_FAILED error in
row_merge_read_clustered_index() and wrongly asserts that
the buffer shouldn't be ran out of memory. Alter table
should give warning when the column value is being
truncated.
When doing a ALTER TABLE ... RENAME, MariaDB doesn't rename
original table to #sql-backup, which it does in other cases,
but insteads drops the original table directly. However
this optimization doesn't work in case of InnoDB table
with a foreign key constraint.
During copy algorithm, InnoDB fails to rename the foreign key
constraint(MDEV-25855). With this optimisation, InnoDB also
fails to drop the original table because the table has
FOREIGN Key constraint exist in INNODB_SYS_FOREIGN table.
This leads to orphan .ibd file in InnoDB dictionary.
so disabling this optimization when FK is involved.
Reviewer: monty@mariadb.org
This fixed the MySQL bug# 20338 about misuse of double underscore
prefix __WIN__, which was old MySQL's idea of identifying Windows
Replace it by _WIN32 standard symbol for targeting Windows OS
(both 32 and 64 bit)
Not that connect storage engine is not fixed in this patch (must be
fixed in "upstream" branch)
MDEV-25604 Atomic DDL: Binlog event written upon recovery does not
have default database
The purpose of this task is to ensure that ALTER TABLE is atomic even if
the MariaDB server would be killed at any point of the alter table.
This means that either the ALTER TABLE succeeds (including that triggers,
the status tables and the binary log are updated) or things should be
reverted to their original state.
If the server crashes before the new version is fully up to date and
commited, it will revert to the original table and remove all
temporary files and tables.
If the new version is commited, crash recovery will use the new version,
and update triggers, the status tables and the binary log.
The one execption is ALTER TABLE .. RENAME .. where no changes are done
to table definition. This one will work as RENAME and roll back unless
the whole statement completed, including updating the binary log (if
enabled).
Other changes:
- Added handlerton->check_version() function to allow the ddl recovery
code to check, in case of inplace alter table, if the table in the
storage engine is of the new or old version.
- Added handler->table_version() so that an engine can report the current
version of the table. This should be changed each time the table
definition changes.
- Added ha_signal_ddl_recovery_done() and
handlerton::signal_ddl_recovery_done() to inform all handlers when
ddl recovery has been done. (Needed by InnoDB).
- Added handlerton call inplace_alter_table_committed, to signal engine
that ddl_log has been closed for the alter table query.
- Added new handerton flag
HTON_REQUIRES_NOTIFY_TABLEDEF_CHANGED_AFTER_COMMIT to signal when we
should call hton->notify_tabledef_changed() during
mysql_inplace_alter_table. This was required as MyRocks and InnoDB
needed the call at different times.
- Added function server_uuid_value() to be able to generate a temporary
xid when ddl recovery writes the query to the binary log. This is
needed to be able to handle crashes during ddl log recovery.
- Moved freeing of the frm definition to end of mysql_alter_table() to
remove duplicate code and have a common exit strategy.
-------
InnoDB part of atomic ALTER TABLE
(Implemented by Marko Mäkelä)
innodb_check_version(): Compare the saved dict_table_t::def_trx_id
to determine whether an ALTER TABLE operation was committed.
We must correctly recover dict_table_t::def_trx_id for this to work.
Before purge removes any trace of DB_TRX_ID from system tables, it
will make an effort to load the user table into the cache, so that
the dict_table_t::def_trx_id can be recovered.
ha_innobase::table_version(): return garbage, or the trx_id that would
be used for committing an ALTER TABLE operation.
In InnoDB, table names starting with #sql-ib will remain special:
they will be dropped on startup. This may be revisited later in
MDEV-18518 when we implement proper undo logging and rollback
for creating or dropping multiple tables in a transaction.
Table names starting with #sql will retain some special meaning:
dict_table_t::parse_name() will not consider such names for
MDL acquisition, and dict_table_rename_in_cache() will treat such
names specially when handling FOREIGN KEY constraints.
Simplify InnoDB DROP INDEX.
Prevent purge wakeup
To ensure that dict_table_t::def_trx_id will be recovered correctly
in case the server is killed before ddl_log_complete(), we will block
the purge of any history in SYS_TABLES, SYS_INDEXES, SYS_COLUMNS
between ha_innobase::commit_inplace_alter_table(commit=true)
(purge_sys.stop_SYS()) and purge_sys.resume_SYS().
The completion callback purge_sys.resume_SYS() must be between
ddl_log_complete() and MDL release.
--------
MyRocks support for atomic ALTER TABLE
(Implemented by Sergui Petrunia)
Implement these SE API functions:
- ha_rocksdb::table_version()
- hton->check_version = rocksdb_check_versionMyRocks data dictionary
now stores table version for each table.
(Absence of table version record is interpreted as table_version=0,
that is, which means no upgrade changes are needed)
- For inplace alter table of a partitioned table, call the underlying
handlerton when checking if the table is ok. This assumes that the
partition engine commits all changes at once.
ALTER TABLE .. RENAME, when used with the inplace algorithm, does:
- Do an inplace or online alter to the new definition
- Rename to new name
- Update triggers.
If update triggers would fail, we would rename the table back.
The problem with this approach is that the table would have the new
definition but the rename would fail. The binary log would also not be
updated.
The solution to this is to very early check if we can rename triggers
and give an error if this would fail.
Both ALTER TABLE ... RENAME and RENAME TABLE is fixed.
This was implemented by moving the pre-check of rename table in triggers
from Table_triggers_list::change_table_name() to
Table_triggers_list::prepare_for_rename().
There are a few different cases to consider
Logging of CREATE TABLE and CREATE TABLE ... LIKE
- If REPLACE is used and there was an existing table, DDL log the drop of
the table.
- If discovery of table is to be done
- DDL LOG create table
else
- DDL log create table (with engine type)
- create the table
- If table was created
- Log entry to binary log with xid
- Mark DDL log completed
Crash recovery:
- If query was in binary log do nothing and exit
- If discoverted table
- Delete the .frm file
-else
- Drop created table and frm file
- If table was dropped, write a DROP TABLE statement in binary log
CREATE TABLE ... SELECT required a little more work as when one is using
statement logging the query is written to the binary log before commit is
done.
This was fixed by adding a DROP TABLE to the binary log during crash
recovery if the ddl log entry was not closed. In this case the binary log
will contain:
CREATE TABLE xxx ... SELECT ....
DROP TABLE xxx;
Other things:
- Added debug_crash_here() functionality to Aria to be able to test
crash in create table between the creation of the .MAI and the .MAD files.
