The loose regex for the MDEV-34539 test ended up
matching the opensuse in the path in buildbot.
Adjust to more complete regex including space,
backtick and \n, which becomes much less common
as a path name.
(Variant 4, with @@optimizer_adjust_secondary_key_costs, reuse in two
places, and conditions are replaced with equivalent simpler forms in two more)
In best_access_path(), ReuseRangeEstimateForRef-3, the check
for whether
"all used key_part_i used key_part_i=const"
was incorrect: it may produced a "NO" answer for cases when we
had:
key_part1= const // some key parts are usable
key_part2= value_not_in_join_prefix //present but unusable
key_part3= non_const_value // unusable due to gap in key parts.
This caused the optimizer to fail to apply ReuseRangeEstimateForRef
heuristics. The consequence is poor query plan choice when the index
in question has very skewed data distribution.
The fix is enabled if its @@optimizer_adjust_secondary_key_costs flag
is set.
The memory leak happened on second execution of a prepared statement
that runs UPDATE statement with correlated subquery in right hand side of
the SET clause. In this case, invocation of the method
table->stat_records()
could return the zero value that results in going into the 'if' branch
that handles impossible where condition. The issue is that this condition
branch missed saving of leaf tables that has to be performed as first
condition optimization activity. Later the PS statement memory root
is marked as read only on finishing first time execution of the prepared
statement. Next time the same statement is executed it hits the assertion
on attempt to allocate a memory on the PS memory root marked as read only.
This memory allocation takes place by the sequence of the following
invocations:
Prepared_statement::execute
mysql_execute_command
Sql_cmd_dml::execute
Sql_cmd_update::execute_inner
Sql_cmd_update::update_single_table
st_select_lex::save_leaf_tables
List<TABLE_LIST>::push_back
To fix the issue, add the flag SELECT_LEX::leaf_tables_saved to control
whether the method SELECT_LEX::save_leaf_tables() has to be called or
it has been already invoked and no more invocation required.
Similar issue could take place on running the DELETE statement with
the LIMIT clause in PS/SP mode. The reason of memory leak is the same as for
UPDATE case and be fixed in the same way.
MySQL-Connector-Net casts SEQ_IN_INDEX to uint and will
raise an exception if the type is a System.Int64.
As we don't support a huge number of multi-columns in
an index reducing to a uint is sufficient to represent
all values and maintain compatibility with MySQL-Connector-Net.
This matches the type (uint) returned by MySQL-8.3 and 8.0.
Reviewer: Alexander Barkov <bar@mariadb.com>
(Variant 2b: call greedy_search() twice, correct handling for limited
search_depth)
Modify the join optimizer to specifically try to produce join orders that
can short-cut their execution for ORDER BY..LIMIT clause.
The optimization is controlled by @@optimizer_join_limit_pref_ratio.
Default value 0 means don't construct short-cutting join orders.
Other value means construct short-cutting join order, and prefer it only
if it promises speedup of more than #value times.
In Optimizer Trace, look for these names:
* join_limit_shortcut_is_applicable
* join_limit_shortcut_plan_search
* join_limit_shortcut_choice
Discovered this while working on MDEV-34720: test_if_cheaper_ordering()
uses rec_per_key, while the original estimate for the access method
is produced in best_access_path() by using actual_rec_per_key().
Make test_if_cheaper_ordering() also use actual_rec_per_key().
Also make several getter function "const" to make this compile.
Also adjusted the testcase to handle this (the change backported from
11.0)
The original code is correct.
valgrind and asan binaries should be built with a specialiced version of
mem_root that makes it easier to find memory overwrites.
This is what the BUILD scripts is doing.
The specialiced mem_root code allocates a new block for every allocation
which is visiable for any test that depenmds on the default original malloc
size and usage.
A mixture of a multi-byte *TEXT column and a short binary column
produced a too large column.
For example, COALESCE(tinytext_utf8mb4, short_varbinary)
produced a BLOB column instead of an expected TINYBLOB.
- Adding a virtual method Type_all_attributes::character_octet_length(),
returning max_length by default.
- Overriding Item_field::character_octet_length() to extract
the octet length from the underlying Field.
- Overriding Item_ref::character_octet_length() to extract
the octet length from the references Item (e.g. as VIEW fields).
- Fixing Type_numeric_attributes::find_max_octet_length() to
take the octet length using the new method character_octet_length()
instead of accessing max_length directly.
New runtime type diagnostic (MDEV-34490) has detected that classes
Item_func_eq, Item_default_value and Item_date_literal_for_invalid_dates
incorrectly return an instance of its ancestor classes when being cloned.
This commit fixes that.
Additionally, it fixes a bug at Item_func_case_simple::do_build_clone()
which led to an endless loop of cloning functions calls.
Reviewer: Oleksandr Byelkin <sanja@mariadb.com>
