MDEV-33502 Slowdown when running nested statement with many partitions
This change was triggered to help some MariaDB users with close to
10000 bits in their bitmaps.
- Change underlaying storage to be 64 bit instead of 32bit.
- This reduses number of loops to scan bitmaps.
- This can cause some bitmaps to be 4 byte large.
- Ensure that all not used top-bits are always 0 (simplifes code as
the last 64 bit storage is not a special case anymore).
- Use my_find_first_bit() to find the first set bit which is much faster
than scanning trough things byte by byte and then bit by bit.
Other things:
- Added a bool to remember if my_bitmap_init() did allocate the bitmap
array. my_bitmap_free() will only free arrays it did allocate.
This allowed me to remove setting 'bitmap=0' before calling
my_bitmap_free() for cases where the bitmap's where allocated externally.
- my_bitmap_init() sets bitmap to 0 in case of failure.
- Added 'universal' asserts to most bitmap functions.
- Change all remaining calls to bitmap_init() to my_bitmap_init().
- To finish the change from 2014.
- Changed all usage of uint32 in my_bitmap.h to my_bitmap_map.
- Updated bitmap_copy() to handle bitmaps of different size.
- Removed const from bitmap_exists_intersection() as this caused casts
on all usage.
- Removed not used function bitmap_set_above().
- Renamed create_last_word_mask() to create_last_bit_mask() (to match
name changes in my_bitmap.cc)
- Extended bitmap-t with test for more bitmap functions.
This patch is the result of running
run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' .
Code style changes have been done on top. The result of this change
leads to the following improvements:
1. Binary size reduction.
* For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by
~400kb.
* A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb.
2. Compiler can better understand the intent of the code, thus it leads
to more optimization possibilities. Additionally it enabled detecting
unused variables that had an empty default constructor but not marked
so explicitly.
Particular change required following this patch in sql/opt_range.cc
result_keys, an unused template class Bitmap now correctly issues
unused variable warnings.
Setting Bitmap template class constructor to default allows the compiler
to identify that there are no side-effects when instantiating the class.
Previously the compiler could not issue the warning as it assumed Bitmap
class (being a template) would not be performing a NO-OP for its default
constructor. This prevented the "unused variable warning".
clang15 finally errors on old prototype definations.
Its also a lot fussier about variables that aren't used
as is the case a number of time with loop counters that
aren't examined.
RocksDB was complaining that its get_range function was
declared without the array length in ha_rocksdb.h. While
a constant is used rather than trying to import the
Rdb_key_def::INDEX_NUMBER_SIZE header (was causing a lot of
errors on the defination of other orders). If the constant
does change can be assured that the same compile warnings will
tell us of the error.
The ha_rocksdb::index_read_map_impl DBUG_EXECUTE_IF was similar
to the existing endless functions used in replication tests.
Its rather moot point as the rocksdb.force_shutdown test that
uses myrocks_busy_loop_on_row_read is currently disabled.
Add a --rocksdb_ignore_datadic_errors plugin option for MyRocks.
The default is 0, and this means MyRocks will call abort() if it detects
a DDL mismatch.
Setting rocksdb_ignore_datadic_errors=1 makes MyRocks to try to ignore the
errors and allow to start the server for repairs.
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.
Insert worked incorrect as well. RocksDB used table->record[0] internally to store some
intermediate results for key conversion, during index searching among other operations.
So table->record[0] is spoiled during ha_rnd_index_map in ha_check_overlaps, so in turn
the broken record data was inserted.
The fix is to store RocksDB intermediate result in its own buffer instead of table->record[0].
`rocksdb` MTR suite is is checked and runs fine.
No need for additional tests. The existing overlaps.test covers the case completely.
However, I am not going to add anything related to rocksdb to suite, to keep it away
from additional dependencies.
To run tests with RocksDB engine, one can add following to engines.combinations:
[rocksdb]
plugin-load=$HA_ROCKSDB_SO
default-storage-engine=rocksdb
rocksdb
Prototype change:
- virtual ha_rows records_in_range(uint inx, key_range *min_key,
- key_range *max_key)
+ virtual ha_rows records_in_range(uint inx, const key_range *min_key,
+ const key_range *max_key,
+ page_range *res)
The handler can ignore the page_range parameter. In the case the handler
updates the parameter, the optimizer can deduce the following:
- If previous range's last key is on the same block as next range's first
key
- If the current key range is in one block
- We can also assume that the first and last block read are cached!
This can be used for a better calculation of IO seeks when we
estimate the cost of a range index scan.
The parameter is fully implemented for MyISAM, Aria and InnoDB.
A separate patch will update handler::multi_range_read_info_const() to
take the benefits of this change and also remove the double
records_in_range() calls that are not anymore needed.
This was done to both simplify the code and also to be easier to handle
storage engines that are clustered on some other index than the primary
key.
As pk_is_clustering_key() and is_clustering_key now are using only
index_flags, these where removed from all storage engines.
MDEV-19486 and one more similar bug appeared because handler::write_row() interface
welcomes to modify buffer by storage engine. But callers are not ready for that
thus bugs are possible in future.
handler::write_row():
handler::ha_write_row(): make argument const
MariaDB doesn't support Read-Free replication, so showing them only causes
confusion.
Removed variables:
- @@rocksdb_read_free_rpl
- @@rocksdb_read_free_rpl_tables
Copy of
commit dcd9379eb5707bc7514a2ff4d9127790356505cb
Author: Manuel Ung <mung@fb.com>
Date: Fri Jun 14 10:38:17 2019 -0700
Skip valgrind for rocksdb.force_shutdown
Summary:
This test does unclean shutdown, and leaks memory.
Squash with: D15749084
Reviewed By: hermanlee
Differential Revision: D15828957
fbshipit-source-id: 30541455d74
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
Move up-to this revision in the upstream:
commit de1e8c7bfe7c875ea284b55040e8f3cd3a56fcc2
Author: Abhinav Sharma <abhinavsharma@fb.com>
Date: Thu Aug 23 14:34:39 2018 -0700
Log updates to semi-sync whitelist in the error log
Summary:
Plugin variable changes are not logged in the error log even when
log_global_var_changes is enabled. Logging updates to whitelist will help in
debugging.
Reviewed By: guokeno0
Differential Revision: D9483807
fbshipit-source-id: e111cda773d
commit de1e8c7bfe7c875ea284b55040e8f3cd3a56fcc2
Author: Abhinav Sharma <abhinavsharma@fb.com>
Date: Thu Aug 23 14:34:39 2018 -0700
Log updates to semi-sync whitelist in the error log
Summary:
Plugin variable changes are not logged in the error log even when
log_global_var_changes is enabled. Logging updates to whitelist will help in
debugging.
Reviewed By: guokeno0
Differential Revision: D9483807
fbshipit-source-id: e111cda773d
RocksDB now supports "iterator bounds" which are min and max keys
that an iterator is interested in.
Iterator initialization function doesn't copy the keys, though, it keeps
pointers to them.
So if the buffer space for the keys is used for another iterator (the one
for checking for UNIUQE constraint violation in ha_rocksdb::ha_update_row)
then one can get incorrect query result.
Fixed by using a separate buffer for iterator bounds in the unique constraint
violation check.
MyRocks internally will print non-critical messages to
sql_print_verbose_info() which will do what InnoDB does in similar cases:
check if (global_system_variables.log_warnings > 2).
- Disallow loading of MyRocks (or any auxilary) plugins after it has been
unloaded.
- Do it carefully - Plugin's system variables may be accesssed (e.g. default
value is set) after the first rocksdb_done_func() call but before
the secon rocksdb_init_func() call.
