(Backported to 10.3, addressed review input)
Sj_materialization_picker::check_qep(): fix error in cost/fanout
calculations:
- for each join prefix, add #prefix_rows / TIME_FOR_COMPARE to the cost,
like best_extension_by_limited_search does
- Remove the fanout produced by the subquery tables.
- Also take into account join condition selectivity
optimize_wo_join_buffering() (used by LooseScan and FirstMatch)
- also add #prefix_rows / TIME_FOR_COMPARE to the cost of each prefix.
- Also take into account join condition selectivity
Problem:-
When mysql executes INSERT ON DUPLICATE KEY INSERT, the storage engine checks
if the inserted row would generate a duplicate key error. If yes, it returns
the existing row to mysql, mysql updates it and sends it back to the storage
engine.When the table has more than one unique or primary key, this statement
is sensitive to the order in which the storage engines checks the keys.
Depending on this order, the storage engine may determine different rows
to mysql, and hence mysql can update different rows.The order that the
storage engine checks keys is not deterministic. For example, InnoDB checks
keys in an order that depends on the order in which indexes were added to
the table. The first added index is checked first. So if master and slave
have added indexes in different orders, then slave may go out of sync.
Solution:-
Make INSERT...ON DUPLICATE KEY UPDATE unsafe while using stmt or mixed format
When there is more then one unique key.
Although there is two exception.
1. Auto Increment key is not counted because Innodb will get gap lock for
failed Insert and concurrent insert will get a next increment value. But if
user supplies auto inc value it can be unsafe.
2. Count only unique keys for which insertion is performed.
So this patch also addresses the bug id #72921
cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Debug
Maintainer mode makes all warnings errors. This patch fix warnings. Mostly about
deprecated `register` keyword.
Too much warnings came from Mroonga and I gave up on it.
Plugin fixed to not lock the LOCK_operations when not active.
Server fixed to lock the LOCK_plugin less - do it once per
thread and then only if a plugin was installed/uninstalled.
truncating a temporary table
TRUNCATE expects only one TABLE instance (which is used by TRUNCATE
itself) to be open. However this requirement wasn't enforced after
"MDEV-5535: Cannot reopen temporary table".
Fixed by closing unused table instances before performing TRUNCATE.
Originally introduced by e972125f1 to avoid harmless wait for
LOCK_global_system_variables in a newly created thread, which creation was
initiated by system variable update.
At the same time it opens dangerous hole, when system variable update
thread already released LOCK_global_system_variables and ack_receiver
thread haven't yet completed new THD construction. In this case THD
constructor goes completely unprotected.
Since ack_receiver.stop() waits for the thread to go down, we have to
temporarily release LOCK_global_system_variables so that it doesn't
deadlock with ack_receiver.run(). Unfortunately it breaks atomicity
of rpl_semi_sync_master_enabled updates and makes them not serialized.
LOCK_rpl_semi_sync_master_enabled was introduced to workaround the above.
TODO: move ack_receiver start/stop into repl_semisync_master
enable_master/disable_master under LOCK_binlog protection?
Part of MDEV-14984 - regression in connect performance
XID_STATE::rm_error is never used by internal 2PC, it is intended to be
used by explicit XA only.
Also removed redundant xid reset from THD::init_for_queries(). Must've
been done already either by THD::transaction constructor or by
THD::cleanup().
Part of MDEV-7974 - backport fix for mysql bug#12161 (XA and binlog)
The command SHOW INDEXES ignored setting of the system variable
use_stat_tables to the value of 'preferably' and and showed statistical
data received from the engine. Similarly queries over the table
STATISTICS from INFORMATION_SCHEMA ignored this setting. It happened
because the function fill_schema_table_by_open() did not read any data
from statistical tables.
This bug is caused by pushdown from HAVING into WHERE.
It appears because condition that is pushed wasn't fixed.
It is also discovered that condition pushdown from HAVING into
WHERE is done wrong. There is no need to build clones for some
conditions that can be pushed. They can be simply moved from HAVING
into WHERE without cloning.
build_pushable_cond_for_having_pushdown(),
remove_pushed_top_conjuncts_for_having() methods are changed.
It is found that there is no transformation made for fields of
pushed condition.
field_transformer_for_having_pushdown transformer is added.
New tests are added. Some comments are changed.
Do not register intermediate tables created by inplace ALTER TABLE in
THD::temporary_tables.
Regular ALTER TABLE doesn't create .frm for temporary and discoverable
tables anymore. For inplace ALTER TABLE moved .frm creation to
create_table_for_inplace_alter().
Removed open_in_engine argument of create_and_open_tmp_table() and
open_temporary_table(): it became unused after this patch.
Part of MDEV-17805 - Remove InnoDB cache for temporary tables.
CREATE TEMPORARY TABLE locks SE plugin 6 times. 5 of these locks are
released by the end of the statement. And only 1 acquired by
init_from_binary_frm_image() / plugin_lock() remains.
The lock removed in this patch was clearly redundant.
Part of MDEV-17805 - Remove InnoDB cache for temporary tables.
The MDEV-17262 commit 26432e49d3
was skipped. In Galera 4, the implementation would seem to require
changes to the streaming replication.
In the tests archive.rnd_pos main.profiling, disable_ps_protocol
for SHOW STATUS and SHOW PROFILE commands until MDEV-18974
has been fixed.
This patch contains a fix for the MDEV-17262/17243 issues and
new mtr test.
These issues (MDEV-17262/17243) have two reasons:
1) After an intermediate commit, a transaction loses its status
of "transaction that registered in the MySQL for 2pc coordinator"
(in the InnoDB) due to the fact that since version 10.2 the
write_row() function (which located in the ha_innodb.cc) does
not call trx_register_for_2pc(m_prebuilt->trx) during the processing
of split transactions. It is necessary to restore this call inside
the write_row() when an intermediate commit was made (for a split
transaction).
Similarly, we need to set the flag of the started transaction
(m_prebuilt->sql_stat_start) after intermediate commit.
The table->file->extra(HA_EXTRA_FAKE_START_STMT) called from the
wsrep_load_data_split() function (which located in sql_load.cc)
will also do this, but it will be too late. As a result, the call
to the wsrep_append_keys() function from the InnoDB engine may be
lost or function may be called with invalid transaction identifier.
2) If a transaction with the LOAD DATA statement is divided into
logical mini-transactions (of the 10K rows) and binlog is rotated,
then in rare cases due to the wsrep handler re-registration at the
boundary of the split, the last portion of data may be lost. Since
splitting of the LOAD DATA into mini-transactions is technical,
I believe that we should not allow these mini-transactions to fall
into separate binlogs. Therefore, it is necessary to prohibit the
rotation of binlog in the middle of processing LOAD DATA statement.
https://jira.mariadb.org/browse/MDEV-17262 and
https://jira.mariadb.org/browse/MDEV-17243
* MDEV-16509 Improve wsrep commit performance with binlog disabled
Release commit order critical section early after trx_commit_low() if
binlog is not transaction coordinator. In order to avoid two phase commit,
binlog_hton is not registered for THD during IO_CACHE population.
Implemented a test which verifies that the transactions release
commit order early.
This optimization will change behavior during recovery as the commit
is not two phase when binlog is off. Fixed and recorded wsrep-recover-v25
and wsrep-recover to match the behavior.
* MDEV-18730 Ordering for wsrep binlog group commit
Previously out of order execution was allowed for wsrep commits.
Established proper ordering by populating wait_for_commit
for every wsrep THD and making group commit leader to wait for
prior commits before proceeding to trx_group_commit_leader().
* MDEV-18730 Added a test case to verify correct commit ordering
* MDEV-16509, MDEV-18730 Review fixes
Use WSREP_EMULATE_BINLOG() macro to decide if the binlog_hton
should be registered. Whitespace/syntax fixes and cleanups.
* MDEV-16509 Require binlog for galera_var_innodb_disallow_writes test
If the commit to InnoDB is done in one phase, the native InnoDB behavior
is that the transaction is committed in memory before it is persisted to
disk. This means that the innodb_disallow_writes=ON may not prevent
transaction to become visible to other readers before commit is completely
over. On the other hand, if the commit is two phase (as it is with binlog),
the transaction will be blocked in prepare phase.
Fixed the test to use binlog, which enforces two phase commit, which
in turn makes commit to block before the changes become visible to
other connections. This guarantees that the test produces expected
result.
The patches features an optional shutdown behavior to hold on until
after all connected slaves have been sent the last binlogged event.
The connected slave is one whose START SLAVE has been acknowledged and
that was not stopped since that though it could be technically
reconnecting in background.
The solution therefore disallows killing the dump thread until is has
found EOF of the latest binlog file. It is up to the shutdown
requester (DBA) to set up a sufficiently large shutdown timeout value
for shudown to wait patiently until lagging behind slaves have been
synchronized. On the other hand if a specific slave needs exclusion
from synchronization the DBA would have to stop it manually which
would terminate its dump thread.
`mysqladmin shutdown' is extended with a `--wait_for_all_slaves' option
which translates to `SHUTDOW WAIT FOR ALL SLAVES' sql query
to enable the feature on the client side.
The patch also performs a small refactoring of the server shutdown
around close_connections() to introduce kill thread phases which
are two as of current.
Make mysqltest to use --ps-protocol more
use prepared statements for everything that server supports
with the exception of CALL (for now).
Fix discovered test failures and bugs.
tests:
* PROCESSLIST shows Execute state, not Query
* SHOW STATUS increments status variables more than in text protocol
* multi-statements should be avoided (see tests with a wrong delimiter)
* performance_schema events have different names in --ps-protocol
* --enable_prepare_warnings
mysqltest.cc:
* make sure run_query_stmt() doesn't crash if there's
no active connection (in wait_until_connected_again.inc)
* prepare all statements that server supports
protocol.h
* Protocol_discard::send_result_set_metadata() should not send
anything to the client.
sql_acl.cc:
* extract the functionality of getting the user for SHOW GRANTS
from check_show_access(), so that mysql_test_show_grants() could
generate the correct column names in the prepare step
sql_class.cc:
* result->prepare() can fail, don't ignore its return value
* use correct number of decimals for EXPLAIN columns
sql_parse.cc:
* discard profiling for SHOW PROFILE. In text protocol it's done in
prepare_schema_table(), but in --ps it is called on prepare only,
so nothing was discarding profiling during execute.
* move the permission checking code for SHOW CREATE VIEW to
mysqld_show_create_get_fields(), so that it would be called during
prepare step too.
* only set sel_result when it was created here and needs to be
destroyed in the same block. Avoid destroying lex->result.
* use the correct number of tables in check_show_access(). Saying
"as many as possible" doesn't work when first_not_own_table isn't
set yet.
sql_prepare.cc:
* use correct user name for SHOW GRANTS columns
* don't ignore verbose flag for SHOW SLAVE STATUS
* support preparing REVOKE ALL and ROLLBACK TO SAVEPOINT
* don't ignore errors from thd->prepare_explain_fields()
* use select_send result for sending ANALYZE and EXPLAIN, but don't
overwrite lex->result, because it might be needed to issue execute-time
errors (select_dumpvar - too many rows)
sql_show.cc:
* check grants for SHOW CREATE VIEW here, not in mysql_execute_command
sql_view.cc:
* use the correct function to check privileges. Old code was doing
check_access() for thd->security_ctx, which is invoker's sctx,
not definer's sctx. Hide various view related errors from the invoker.
sql_yacc.yy:
* initialize lex->select_lex for LOAD, otherwise it'll contain garbage
data that happen to fail tests with views in --ps (but not otherwise).
