This patch introduces support for the system variable eq_range_index_dive_limit
that existed in MySQL starting from 5.6. The variable sets a limit for
index dives into equality ranges. Index dives are performed by optimizer
to estimate the number of rows in range scans. Index dives usually provide
good estimate but they are pretty expensive. To estimate the number of rows
in equality ranges statistical data on indexes can be employed. Its usage gives
not so good estimates but it's cheap. So if the number of equality dives
required by an index scan exceeds the set limit no dives for equality
ranges are performed by the optimizer for this index.
As the new system variable is introduced in a stable version the default
value for it is set to a special value meaning there is no limit for the number
of index dives performed by the optimizer.
The patch partially uses the MySQL code for WL 5957
'Statistics-based Range optimization for many ranges'.
This concludes the merge of all applicable InnoDB changes from
MySQL 5.7.23, with the exception of a performance fix, which we
plan to rewrite in MariaDB later in such a way that it does not
involve changing the storage engine API:
MDEV-16849 Extending indexed VARCHAR column should be instantaneous
Introduce the configuration option innodb_log_optimize_ddl
for controlling whether native index creation or table-rebuild
in InnoDB should keep optimizing the redo log
(and writing MLOG_INDEX_LOAD records to ensure that
concurrent backup would fail).
By default, we have innodb_log_optimize_ddl=ON, that is,
the default behaviour that was introduced in MariaDB 10.2.2
(with the merge of InnoDB from MySQL 5.7) will be unchanged.
BtrBulk::m_trx: Replaces m_trx_id. We must be able to check for
KILL QUERY even if !m_flush_observer (innodb_log_optimize_ddl=OFF).
page_cur_insert_rec_write_log(): Declare globally, so that this
can be called from PageBulk::insert().
row_merge_insert_index_tuples(): Remove the unused parameter trx_id.
row_merge_build_indexes(): Enable or disable redo logging based on
the innodb_log_optimize_ddl parameter.
PageBulk::init(), PageBulk::insert(), PageBulk::finish(): Write
redo log records if needed. For ROW_FORMAT=COMPRESSED, redo log
will be written in PageBulk::compress() unless we called
m_mtr.set_log_mode(MTR_LOG_NO_REDO).
The parameter innodb_lock_schedule_algorithm was introduced in
MariaDB Server 10.1.19, 10.2.13, 10.3.4 as part of MDEV-11039.
In MariaDB 10.1, the default value of the parameter is 'fcfs',
that is, the existing algorithm is used by default. But in
later versions of MariaDB Server, the parameter was 'vats',
enabling the new algorithm.
Because the new algorithm is triggering a debug assertion failure
that suggests corruption of the transactional lock data structures,
we will revert to the old algorithm by default until we have
resolved the problem.
The upper 1M limit for max_prepared_stmt_count was set over 10 years
ago. It doesn't suite current hardware and a sysbench oltp_read_write
test with 512 threads will hit this limit.
MDEV--15609 engines/funcs.crash_manytables_number crashes with error 24
(too many open files)
MDEV-10286 Adjustment of table_open_cache according to system limits
does not work when open-files-limit option is provided
Fixed by adjusting tc_size downwards if there is not enough file
descriptors to use.
Other changes:
- Ensure that there is 30 (was 10) extra file descriptors for other usage
- Decrease TABLE_OPEN_CACHE_MIN to 200 as it's better to have a smaller
table cache than getting error 24
- Increase minimum of max_connections and table_open_cache from 1 to 10
as 1 is not usable for any real application, only for testing.
fix galera.galera_sst_mysqldump test to work:
* must connect to 127.0.0.1, where mysqld is listening
* disable wsrep_sync_wait in wsrep_sst_mysqldump, otherwise
sst can deadlock
* allow 127.0.0.1 for bind_address and wsrep_sst_receive_address.
(it's useful in tests, or when two nodes are on the same box,
or when nodes are on different boxes, but the connection is
tunelled, or whatever. Don't judge user's setup). MDEV-14070
* don't wait for client connections to die when doing
mysqldump sst. they'll die in a due time, and if needed mysql
will wait on locks until they do. MDEV-14069
Also don't mark it big, to make sure it's sufficiently tested
InnoDB in Debian uses utf8mb4 as default character set since
version 10.0.20-2. This leads to major pain due to keys longer
than 767 bytes.
MariaDB 10.2 (and MySQL 5.7) introduced the setting
innodb_default_row_format that is DYNAMIC by default. These
versions also changed the default values of the parameters
innodb_large_prefix=ON and innodb_file_format=Barracuda.
This would allow longer column index prefixes to be created.
The original purpose of these parameters was to allow InnoDB
to be downgraded to MySQL 5.1, which is long out of support.
Every InnoDB version since MySQL 5.5 does support operation
with the relaxed limits.
We backport the parameter innodb_default_row_format to
MariaDB 10.1, but we will keep its default value at COMPACT.
This allows MariaDB 10.1 to be configured so that CREATE TABLE
is less likely to encounter a problem with the limitation:
loose_innodb_large_prefix=ON
loose_innodb_default_row_format=DYNAMIC
(Note that the setting innodb_large_prefix was deprecated in
MariaDB 10.2 and removed in MariaDB 10.3.)
The only observable difference in the behaviour with the default
settings should be that ROW_FORMAT=DYNAMIC tables can be created
both in the system tablespace and in .ibd files, no matter what
innodb_file_format has been assigned to. Unlike MariaDB 10.2,
we are not changing the default value of innodb_file_format,
so ROW_FORMAT=COMPRESSED tables cannot be created without
changing the parameter.
Two follow-up tasks were filed for MySQL 5.7.21 changes that
were not applied here:
MDEV-15179 performance_schema.file_instances does not reflect RENAME TABLE
MDEV-14222 Unnecessary 'cascade' memory allocation for every updated
row when there is no FOREIGN KEY
This is 10.1 version where no merge error exists.
wsrep_on_check
New check function. Galera can't be enabled
if innodb-lock-schedule-algorithm=VATS.
innobase_kill_query
In Galera async kill we could own lock mutex.
innobase_init
If Variance-Aware-Transaction-Sheduling Algorithm (VATS) is
used on Galera we refuse to start InnoDB.
Changed innodb-lock-schedule-algorithm as read-only parameter
as it was designed to be.
lock_rec_other_has_expl_req,
lock_rec_other_has_conflicting,
lock_rec_lock_slow
lock_table_other_has_incompatible
lock_rec_insert_check_and_lock
Change pointer to conflicting lock to normal pointer as this
pointer contents could be changed later.
- innodb_buffer_pool_dump_now_basic is modified to make sure it
really performs a dump and waits till it completion, to avoid
the apparent or hidden failure similar to MDEV-9713 / MDEV-10651
- innodb_buffer_pool_dump_pct_basic is modified to re-use the new
code from innodb_buffer_pool_dump_now_basic and thus avoid
the failure MDEV-10651
- innodb_buffer_pool_load_now_basic is re-written to simplify
the logic by re-using the code innodb_buffer_pool_dump_now_basic
and is given an opt file to avoid race conditions with
buffer pool load performed upon server startup, which causes
MDEV-14196 failure
The InnoDB purge subsystem can be best stopped by opening a read view,
for example by START TRANSACTION WITH CONSISTENT SNAPSHOT.
To ensure that everything is purged, use wait_all_purged.inc,
which waits for the History list length in SHOW ENGINE INNODB STATUS
to reach 0. Setting innodb_purge_run_now never guaranteed this.
