When one session SELECT ... FOR UPDATE and holds the lock, subsequent
sessions that SELECT ... FOR UPDATE will wait to get the lock.
Currently, that event is labeled as `wait/io/table/sql/handler`, which
is incorrect. Instead, it should have been
`wait/lock/table/sql/handler`.
Two factors contribute to this bug:
1. Instrumentation interface and the heavy usage of `TABLE_IO_WAIT` in
`sql/handler.cc` file. See interface [^1] for better understanding;
2. The balancing act [^2] of doing instrumentation aggregration _AND_
having good performance. For example, EVENTS_WAITS_SUMMARY... is
aggregated using EVENTS_WAITS_CURRENT. Aggregration needs to be based
on the same wait class, and the code was overly aggressive in label a
LOCK operation as an IO operation in this case.
The proposed fix is pretty simple, but understanding the bug took a
while. Hence the footnotes below. For future improvement and
refactoring, we may want to consider renaming `TABLE_IO_WAIT` and making
it less coarse and more targeted.
Note that newly added test case, events_waits_current_MDEV-29091,
initially didn't pass Buildbot CI for embedded build tests. Further
research showed that other impacted tests all included not_embedded.inc.
This oversight was fixed later.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.
[^1]: To understand `performance_schema` instrumentation interface, I
found this URL is the most helpful:
https://dev.mysql.com/doc/dev/mysql-server/latest/PAGE_PFS_PSI.html
[^2]: The best place to understand instrumentation projection,
composition, and aggregration is through the source file. Although I
prefer reading Doxygen produced html file, but for whatever reason, the
rendering is not ideal. Here is link to 10.6's pfs.cc:
https://github.com/MariaDB/server/blob/10.6/storage/perfschema/pfs.cc
MDEV-28227 added the error messages in simplified characters.
Lets use these for those running a zh_CN profile.
From Haidong Ji in the MDEV, Taiwan/Hong Kong (zh_TW/zh_HK)
would expect traditional characters so this is left for when
we have these.
Add .gitlab-ci.yml file to earliest supported branch to enable
automated building and testing for all MariaDB major branches.
For 10.4 we use the bundled SSL to build MariaDB when the platform
does not have OpenSSL 1.1 available. This requires the installation of
gnutls-devel as a dependency of MariaDB Connector/C.
OpenSSL 3.0 support was backported to MariaDB 10.5
(see https://github.com/MariaDB/server/pull/2036, f0fa40ef, 8a9c1e9c)
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
- InnoDB tries to build the previous version of the record for
the virtual index, but the undo log record doesn't contain
virtual column information. This leads to assert failure while
building the tuple.
ha_partition doesn't forward Rowid Filter API calls to the storage
engines handling partitions.
An attempt to use rowid filtering with caused either
- Rowid Filter being shown in EXPLAIN but not actually used
- Assertion failure when subquery code tried to disable/enable rowid
filter, which was not present.
Fixed by returning correct flags from ha_partition::index_flags()
One of the constraints added in the MDEV-29639 patch, is that only
the first event after idling should update last_master_timestamp;
and as long as the replica has more events to execute, the variable
should not be updated. The corresponding test,
rpl_delayed_parallel_slave_sbm.test, aims to verify this; however,
if the IO thread takes too long to queue events, the SQL thread can
appear to catch up too fast.
This fix ensures that the relay log has been fully written before
executing the events.
Note that the underlying cause of this test failure needs to be
addressed as a bug-fix, this is a temporary fix to stop test
failures. To track work on the bug-fix for the underlying issue,
please see MDEV-30619.
The parser code for single-table DELETE missed the call of the function
LEX::check_main_unit_semantics(). As a result the the field nested level
of SELECT_LEX structures remained set 0 for all non-top level selects.
This could lead to different kind of problems. In particular this did not
allow to determine properly the selects where set functions had to be
aggregated when they were used in inner subqueries.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
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".
The -D flag was not passed to asm compiler, despite SET_PROPERTY(COMPILE_OPTIONS)
The exact reason for that remains unknown. It was not seen with gcc, as
nor was be reproduced on newer CMake.
The existing storage/rocksdb/CMakeCache.txt defined
ATOMIC_EXTRA_LIBS when atomics where required. This was
determined by the toplevel configure.cmake test
(HAVE_GCC_C11_ATOMICS_WITH_LIBATOMIC).
As build_rocksdb.cmake is included after ATOMIC_EXTRA_LIBS
was set, we just need to use it. As such no riscv64
specific macro is needed in build_rocksdb.cmake.
As highlighted by Gianfranco Costamagna (@LocutusOfBorg)
in #2472 overwriting SYSTEM_LIBS was problematic.
This is corrected in case in future SYSTEM_LIBS is changed
elsewhere.
Closes#2472.
The error string from ER_KILL_QUERY_DENIED_ERROR took a different
type to ER_KILL_DENIED_ERROR for the thread id. This shows
up in differences on 32 big endian arches like powerpc (Deb notation).
Normalize the passing of the THD->id to its real type of my_thread_id,
and cast to (long long) on output. As such normalize the
ER_KILL_QUERY_DENIED_ERROR to that convention too.
Note for upwards merge, convert the type to %lld on new translations
of ER_KILL_QUERY_DENIED_ERROR.
This patch allowed transformation of EXISTS subqueries into equivalent
IN predicands at the top level of WHERE conditions for multi-table UPDATE
and DELETE statements. There was no reason to prohibit the transformation
for such statements. The transformation provides more opportunities of
using semi-join optimizations.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
The function spider_db_mbase::print_warnings() can potentially result
in a null pointer dereference.
Remove the null pointer dereference by cleaning up the function.
Some small changes to the original commit
422fb63a9b.
Co-Authored-By: Yuchen Pei <yuchen.pei@mariadb.com>
Following tests do not test anymore what they intended to test
deleted: suite/galera/t/MDEV-24143.test
deleted: suite/galera/t/galera_bf_abort_get_lock.test
Enable use of Rowid Filter optimization with eq_ref access.
Use the following assumptions:
- Assume index-only access cost is 50% of non-index-only access cost.
- Take into account that "Eq_ref access cache" reduces the number of
lookups eq_ref access will make.
= This means the number of Rowid Filter checks is reduced also
= Eq_ref access cost is computed using that assumption (see
prev_record_reads() call), so we should use it in all cost '
computations.
This patch fixes the problem by adding a new rule booleat_test.
This makes the grammar clearer and less conflicting.
Additionally, fixing %prec in this grammar branch:
- | boolean_test IS NULL_SYM %prec PREC_BELOW_NOT
+ | boolean_test IS NULL_SYM %prec IS
to have consistently "%prec IS" in all grammar branches starting
with "boolean_test IS ...".
It's not clear why these three rules needed different %prec before the fix:
- boolean_test IS TRUE
- boolean_test IS UNKNOWN
- boolean_test IS NULL
This bug manifested itself when the server processed a query containing
a derived table over union whose ORDER BY clause included a subquery
with unresolvable column reference. For such a query the server crashed
when trying to resolve column references in the ORDER BY clause used by
union.
For any union with ORDER BY clause an extra SELECT_LEX structure is created
and it is attached to SELECT_LEX_UNIT structure of the union via the field
fake_select_lex. The outer context for fake_select_lex must be the same as
for other selects of the union. If the union is used in the FROM list of
a derived table then the outer context for fake_select_lex must be set to
NULL in line with other selects of the union. It was not done and it
caused a crash when searching for possible resolution of an unresolvable
column reference occurred in a subquery used in the ORDER BY clause.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
This is Kentoku's patch for MDEV-22979 (e6e41f04f4 + 22a0097727),
which fixes 30370.
It changes the wait to a timed wait for the first sts thread, which
waits on server start to execute the init queries for spider. It also
flips the flag init_command to false when the sts thread is being
freed. With these changes the sts thread can check the flag regularly
and abort the init_queries when it finds out the init_command is
false. This avoids the deadlock that causes the problem in MDEV-30370.
It also fixes MDEV-22979 for 10.4, but not 10.5. I have not tested
higher versions for MDEV-22979.
A test has also been done on MDEV-29904 to avoid regression, given
MDEV-27233 is a similar problem and its patch caused the
regression. The test passes for 10.4-11.0.
However, this adhoc test only works consistently when placed in the
main testsuite. We should not place spider tests in the main suite, so
we do not include it in this commit. A patch for MDEV-27912 should fix
this problem and allow a proper test for MDEV-29904. See comments in
the jira ticket MDEV-30370/29904 for the adhoc testcase used for this
commit.
ANALYZE was observed to race over a preceding in binlog order DML
in updating the binlog and slave gtid states.
Tagging ANALYZE and other admin class commands in binlog by the fixes
of MDEV-17515 left a flaw allowing such race leading to
the gtid mode out-of-order error.
This is fixed now to observe by ADMIN commands the ordered access to
the slave gtid status variables and binlog.
This commit merely adds is a Read-Committed version MDEV-30225 test
solely to prove the RC isolation yields ROW binlog format as it is
supposed to per docs.
This bug manifested itself in very rare situations when splitting
optimization was applied to a materialized derived table with group clause
by key over a constant meargeable derived table that was in inner part of
an outer join. In this case the used tables for the key to access the
split table incorrectly was evaluated to a not empty table map.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
Problem
========
On a parallel, delayed replica, Seconds_Behind_Master will not be
calculated until after MASTER_DELAY seconds have passed and the
event has finished executing, resulting in potentially very large
values of Seconds_Behind_Master (which could be much larger than the
MASTER_DELAY parameter) for the entire duration the event is
delayed. This contradicts the documented MASTER_DELAY behavior,
which specifies how many seconds to withhold replicated events from
execution.
Solution
========
After a parallel replica idles, the first event after idling should
immediately update last_master_timestamp with the time that it began
execution on the primary.
Reviewed By
===========
Andrei Elkin <andrei.elkin@mariadb.com>
This patch fixes the patch for bug MDEV-30248 that unsatisfactorily
resolved the problem of resolution of references to CTE. In some cases
when such a reference has the same table name as the name of one of
CTEs containing this reference the reference could be resolved incorrectly
that led to an invalid select tree where units could be mutually dependent.
This in its turn could lead to an infinite sequence of recursive calls or
to falls into infinite loops.
The patch also removes LEX::resolve_references_to_cte_in_hanging_cte() as
with the new code for resolution of CTE references the call of this
function is not needed anymore.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
(Initial patch by Varun Gupta. Amended and added comments).
When the query has both
1. Aggregate functions that require sorting data by group, and
2. Window functions
we need to use two temporary tables. The first temp.table will hold the
join output. Then it is passed to filesort(). Reading it in sorted
order allows to compute the aggregate functions.
Then, we need to write their values into the second temp. table. Then,
Window Function computation step can pass that to filesort() and read
them in the order it needs.
Failure to create the second temp. table would cause an assertion
failure: window function could would not find where to get the values
of the aggregate functions.
disable bulk insert optimization if long uniques are used, because they
need to read the table (index_read) after every inserted now. And bulk
insert optimization might disable indexes.
bulk insert is already disabled in other cases when there are chances
that the table will be read duing the bulk insert.
