- In 10.6, trx_rseg_t mutex was ported to use latch. As part of this porting
profiling of the patch was removed. This patch reenables it given that
the said latch continues to occupy the top-slots in the contention list.
A prominent bottleneck in mtr_t::commit() is log_sys.mutex between
log_sys.append_prepare() and log_close().
User-visible change: The minimum innodb_log_file_size will be
increased from 1MiB to 4MiB so that some conditions can be
trivially satisfied.
log_sys.latch (log_latch): Replaces log_sys.mutex and
log_sys.flush_order_mutex. Copying mtr_t::m_log to
log_sys.buf is protected by a shared log_sys.latch.
Writes from log_sys.buf to the file system will be protected
by an exclusive log_sys.latch.
log_sys.lsn_lock: Protects the allocation of log buffer
in log_sys.append_prepare().
sspin_lock: A simple spin lock, for log_sys.lsn_lock.
Thanks to Vladislav Vaintroub for suggesting this idea, and for
reviewing these changes.
mariadb-backup: Replace some use of log_sys.mutex with recv_sys.mutex.
buf_pool_t::insert_into_flush_list(): Implement sorting of flush_list
because ordering is otherwise no longer guaranteed. Ordering by LSN
is needed for the proper operation of redo log checkpoints.
log_sys.append_prepare(): Advance log_sys.lsn and log_sys.buf_free by
the length, and return the old values. Also increment write_to_buf,
which was previously done in log_close().
mtr_t::finish_write(): Obtain the buffer pointer from
log_sys.append_prepare().
log_sys.buf_free: Make the field Atomic_relaxed,
to simplify log_flush_margin(). Use only loads and stores
to avoid costly read-modify-write atomic operations.
buf_pool.flush_list_requests: Replaces
export_vars.innodb_buffer_pool_write_requests
and srv_stats.buf_pool_write_requests.
Protected by buf_pool.flush_list_mutex.
buf_pool_t::insert_into_flush_list(): Do not invoke page_cleaner_wakeup().
Let the caller do that after a batch of calls.
recv_recover_page(): Invoke a minimal part of
buf_pool.insert_into_flush_list().
ReleaseBlocks::modified: A number of pages added to buf_pool.flush_list.
ReleaseBlocks::operator(): Merge buf_flush_note_modification() here.
log_t::set_capacity(): Renamed from log_set_capacity().
Fixup for MDEV-10075
Analysis: ERROR_INDEX implemented in MDEV-10075 was not intuitively clear.
Fix: changed parser to use ROW_NUMBER instead of ERROR_INDEX. Removed
ERROR_INDEX and ERROR_INDEX_SYM from related files. Changed m_error_index
to m_row_number.
- DISCARD/IMPORT TABLESPACE are the only tablespace commands left
- TABLESPACE arguments for CREATE TABLE and ALTER ... ADD PARTITION are
ignored.
- Tablespace names are not shown anymore in .frm and not shown in
information schema
Other things
- Removed end spaces from sql/CMakeList.txt
Improve documentation of performance_schema tables by appending COLUMN
comments to tables. Additionally improve test coverage and update corresponding
tests.
This is part of the patch covering newer columns and tables in 10.5.
Improve documentation of performance_schema tables by appending COLUMN
comments to tables. Additionally improve test coverage and update corresponding
tests.
In the parent commit, dict_sys.latch could theoretically have been
replaced with a mutex. But, we can do better and merge dict_sys.mutex
into dict_sys.latch. Generally, every occurrence of dict_sys.mutex_lock()
will be replaced with dict_sys.lock().
The PERFORMANCE_SCHEMA instrumentation for dict_sys_mutex
will be removed along with dict_sys.mutex. The dict_sys.latch
will remain instrumented as dict_operation_lock.
Some use of dict_sys.lock() will be replaced with dict_sys.freeze(),
which we will reintroduce for the new shared mode. Most notably,
concurrent table lookups are possible as long as the tables are present
in the dict_sys cache. In particular, this will allow more concurrency
among InnoDB purge workers.
Because dict_sys.mutex will no longer 'throttle' the threads that purge
InnoDB transaction history, a performance degradation may be observed
unless innodb_purge_threads=1.
The table cache eviction policy will become FIFO-like,
similar to what happened to fil_system.LRU
in commit 45ed9dd957.
The name of the list dict_sys.table_LRU will become somewhat misleading;
that list contains tables that may be evicted, even though the
eviction policy no longer is least-recently-used but first-in-first-out.
(Note: Tables can never be evicted as long as locks exist on them or
the tables are in use by some thread.)
As demonstrated by the test perfschema.sxlock_func, there
will be less contention on dict_sys.latch, because some previous
use of exclusive latches will be replaced with shared latches.
fts_parse_sql_no_dict_lock(): Replaced with pars_sql().
fts_get_table_name_prefix(): Merged to fts_optimize_create().
dict_stats_update_transient_for_index(): Deduplicated some code.
ha_innobase::info_low(), dict_stats_stop_bg(): Use a combination
of dict_sys.latch and table->stats_mutex_lock() to cover the
changes of BG_STAT_SHOULD_QUIT, because the flag is being read
in dict_stats_update_persistent() while not holding dict_sys.latch.
row_discard_tablespace_for_mysql(): Protect stats_bg_flag by
exclusive dict_sys.latch, like most other code does.
row_quiesce_table_has_fts_index(): Remove unnecessary mutex
acquisition. FLUSH TABLES...FOR EXPORT is protected by MDL.
row_import::set_root_by_heuristic(): Remove unnecessary mutex
acquisition. ALTER TABLE...IMPORT TABLESPACE is protected by MDL.
row_ins_sec_index_entry_low(): Replace a call
to dict_set_corrupted_index_cache_only(). Reads of index->type
were not really protected by dict_sys.mutex, and writes
(flagging an index corrupted) should be extremely rare.
dict_stats_process_entry_from_defrag_pool(): Only freeze the dictionary,
do not lock it exclusively.
dict_stats_wait_bg_to_stop_using_table(), DICT_BG_YIELD: Remove trx.
We can simply invoke dict_sys.unlock() and dict_sys.lock() directly.
dict_acquire_mdl_shared()<trylock=false>: Assert that dict_sys.latch is
only held in shared more, not exclusive mode. Only acquire it in
exclusive mode if the table needs to be loaded to the cache.
dict_sys_t::acquire(): Remove. Relocating elements in dict_sys.table_LRU
would require holding an exclusive latch, which we want to avoid
for performance reasons.
dict_sys_t::allow_eviction(): Add the table first to dict_sys.table_LRU,
to compensate for the removal of dict_sys_t::acquire(). This function
is only invoked by INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS.
dict_table_open_on_id(), dict_table_open_on_name(): If dict_locked=false,
try to acquire dict_sys.latch in shared mode. Only acquire the latch in
exclusive mode if the table is not found in the cache.
Reviewed by: Thirunarayanan Balathandayuthapani
the test tests whether short options work on the server command line
* remove 'show variables' for variables not affected by short options
* remove options, that are not short
* remove options, that cannot be tested from SQL
* in particular, -T12 doesn't affect the test output,
but cases ~30sec delay on shutdown
* use -W1 as -W2 is the default, so doesn't affect the test output
report correct error codes in ed25519.
Invalid value stored in the user table or an OpenSSL error is CR_ERROR.
When a user provided incorrect password when logging in -
it's CR_AUTH_USER_CREDENTIALS.
The ROWNUM() function is for SELECT mapped to JOIN->accepted_rows, which is
incremented for each accepted rows.
For Filesort, update, insert, delete and load data, we map ROWNUM() to
internal variables incremented when the table is changed.
The connection between the row counter and Item_func_rownum is done
in sql_select.cc::fix_items_after_optimize() and
sql_insert.cc::fix_rownum_pointers()
When ROWNUM() is used anywhere in query, the optimization to ignore ORDER
BY in sub queries are disabled. This was done to get the following common
Oracle query to work:
select * from (select * from t1 order by a desc) as t where rownum() <= 2;
MDEV-3926 "Wrong result with GROUP BY ... WITH ROLLUP" contains a discussion
about this topic.
LIMIT optimization is enabled when in a top level WHERE clause comparing
ROWNUM() with a numerical constant using any of the following expressions:
- ROWNUM() < #
- ROWNUM() <= #
- ROWNUM() = 1
ROWNUM() can be also be the right argument to the comparison function.
LIMIT optimization is done in two cases:
- For the current sub query when the ROWNUM comparison is done on the top
level:
SELECT * from t1 WHERE rownum() <= 2 AND t1.a > 0
- For an inner sub query, when the upper level has only a ROWNUM comparison
in the WHERE clause:
SELECT * from (select * from t1) as t WHERE rownum() <= 2
In Oracle mode, one can also use ROWNUM without parentheses.
Other things:
- Fixed bug where the optimizer tries to optimize away sub queries
with RAND_TABLE_BIT set (non-deterministic queries). Now these
sub queries will not be converted to joins. This bug fix was also
needed to get rownum() working inside subqueries.
- In remove_const() remove setting simple_order to FALSE if ROLLUP is
USED. This code was disable a long time ago because of wrong assignment
in the following code. Instead we set simple_order to false if
RAND_TABLE_BIT was used in the SELECT list. This ensures that
we don't delete ORDER BY if the result set is not deterministic, like
in 'SELECT RAND() AS 'r' FROM t1 ORDER BY r';
- Updated parameters for Sort_param::init_for_filesort() to be able
to provide filesort with information where the number of accepted
rows should be stored
- Reordered fields in class Filesort to optimize storage layout
- Added new error messsage to tell that a function can't be used in HAVING
- Added field 'with_rownum' to THD to mark that ROWNUM() is used in the
query.
Co-author: Oleksandr Byelkin <sanja@mariadb.com>
LIMIT optimization for sub query
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
Merge 'replication_applier_status_by_coordinator' table.
This table captures SQL_THREAD status in case of both single threaded and
multi threaded slave configuration. When multi_source replication is enabled
this table will display each source specific SQL_THREAD status.
Added new columns for:
- LAST_SEEN_TRANSACTION
- LAST_TRANS_RETRY_COUNT
Merge 'replication_connection_configuration' table.
Replaced following column:
- AUTO_POSITION with USING_GTID
Added new columns for:
- IGNORE_SERVER_IDS
- DO_DOMAIN_IDS
- IGNORE_SERVER_IDS
Removed following columns as they are not part of mariadb replication
connection configuration:
- NETWORK_INTERFACE
- TLS_VERSION
@sql/mysqld.cc
Changed "master-retry-count" default value to 100000.
Step2:
=====
Add two extra columns mentioned below.
---------------------------------------------------------------------------
|Column Name: | Description: |
|-------------------------------------------------------------------------|
| | |
|WORKER_IDLE_TIME | Total idle time in seconds that the worker |
| | thread has spent waiting for work from |
| | co-ordinator thread |
| | |
|LAST_TRANS_RETRY_COUNT | Total number of retries attempted by last |
| | transaction |
---------------------------------------------------------------------------
Step1:
=====
Backport 'replication_applier_status_by_worker' from upstream.
Iterate through rpl_parallel_thread_pool and display slave worker thread
specific information as part of 'replication_applier_status_by_worker'
table.
---------------------------------------------------------------------------
|Column Name: | Description: |
|-------------------------------------------------------------------------|
| | |
|CHANNEL_NAME | Name of replication channel through which the |
| | transaction is received. |
| | |
|THREAD_ID | Thread_Id as displayed in 'performance_schema. |
| | threads' table for thread with name |
| | 'thread/sql/rpl_parallel_thread' |
| | |
| | THREAD_ID will be NULL when worker threads are |
| | stopped due to an error/force stop |
| | |
|SERVICE_STATE | Thread is running or not |
| | |
|LAST_SEEN_TRANSACTION | Last GTID executed by worker |
| | |
|LAST_ERROR_NUMBER | Last Error that occured on a particular worker |
| | |
|LAST_ERROR_MESSAGE | Last error specific message |
| | |
|LAST_ERROR_TIMESTAMP | Time stamp of last error |
| | |
---------------------------------------------------------------------------
CHANNEL_NAME will be empty when the worker has not processed any
transaction. Channel_name points to valid source channel_name when it is
processing a transaction/event group.
Adds an implementation for SELECT ... FOR UPDATE SKIP LOCKED /
SELECT ... LOCK IN SHARED MODE SKIP LOCKED
This is implemented only InnoDB at the moment, not in RockDB yet.
This adds a new hander flag HA_CAN_SKIP_LOCKED than
will be used when the storage engine advertises the flag.
When a storage engine indicates this flag it will get
TL_WRITE_SKIP_LOCKED and TL_READ_SKIP_LOCKED transaction types.
The Lex structure has been updated to store both the FOR UPDATE/LOCK IN
SHARE as well as the SKIP LOCKED so the SHOW CREATE VIEW
implementation is simplier.
"SELECT FOR UPDATE ... SKIP LOCKED" combined with CREATE TABLE AS or
INSERT.. SELECT on the result set is not safe for STATEMENT based
replication. MIXED replication will replicate this as row based events."
Thanks to guidance from Facebook commit
193896c466
This helped verify basic test case, and components that need implementing
(even though every part was implemented differently).
Thanks Marko for guidance on simplier InnoDB implementation.
Reviewers: Marko, Monty
