A bug in the code of the function key_or could lead to a situation
when performing of an OR operation for one index changes the result
the operation for another index. This bug is fixed with this patch.
Also corrected the specification and the code of the function
or_sel_tree_with_checks.
In MariaDB, when running in ONLY_FULL_GROUP_BY mode,
the server produced in incorrect error message that there
is an aggregate function without GROUP BY, for artificially
created MIN/MAX functions during subquery MIN/MAX optimization.
The fix introduces a way to distinguish between artifially
created MIN/MAX functions as a result of a rewrite, and normal
ones present in the query. The test for ONLY_FULL_GROUP_BY violation
now tests in addition if a MIN/MAX function was part of a MIN/MAX
subquery rewrite.
In order to be able to distinguish these MIN/MAX functions, the
patch introduces an additional flag in Item_in_subselect::in_strategy -
SUBS_STRATEGY_CHOSEN. This flag is set when the optimizer makes its
final choice of a subuqery strategy. In order to make the choice
consistent, access to Item_in_subselect::in_strategy is provided
via new class methods.
******
Fix MySQL BUG#12329653
In MariaDB, when running in ONLY_FULL_GROUP_BY mode,
the server produced in incorrect error message that there
is an aggregate function without GROUP BY, for artificially
created MIN/MAX functions during subquery MIN/MAX optimization.
The fix introduces a way to distinguish between artifially
created MIN/MAX functions as a result of a rewrite, and normal
ones present in the query. The test for ONLY_FULL_GROUP_BY violation
now tests in addition if a MIN/MAX function was part of a MIN/MAX
subquery rewrite.
In order to be able to distinguish these MIN/MAX functions, the
patch introduces an additional flag in Item_in_subselect::in_strategy -
SUBS_STRATEGY_CHOSEN. This flag is set when the optimizer makes its
final choice of a subuqery strategy. In order to make the choice
consistent, access to Item_in_subselect::in_strategy is provided
via new class methods.
The function add_ref_to_table_cond missed updating the value of
join_tab->pre_idx_push_select_cond after having updated the value
of join_tab->select->pre_idx_push_select_cond.
The bug was accidentally fixed by fixing
Bug#11759688 52020: InnoDB can still deadlock on just INSERT...ON DUPLICATE KEY
a.k.a. the reintroduction of
Bug#7975 deadlock without any locking, simple select and update
a.k.a. Bug#7975 deadlock without any locking, simple select and update
Bug#7975 was reintroduced when the storage engine API was made
pluggable in MySQL 5.1. Instead of looking at thd->lex directly, we
rely on handler::extra(). But, we were looking at the wrong extra()
flag, and we were ignoring the TRX_DUP_REPLACE flag in places where we
should obey it.
innodb_replace.test: Add tests for hopefully all affected statement
types, so that bug should never ever resurface. This kind of tests
should have been added when fixing Bug#7975 in MySQL 5.0.3 in the
first place.
rb:806 approved by Sunny Bains
btr_pcur_restore_position_func(): When the cursor was positioned at
the tree infimum or supremum, initialize pos_state and latch_mode. The
assertion failed, because pos_state was BTR_PCUR_WAS_POSITIONED. In
the test failure of WL#5874, the purge thread attempted to restore the
cursor position on the infimum record (the clustered index was empty).
btr_pcur_detach(), btr_pcur_is_detached(): Unused functions, remove.
rb:804 approved by Inaam Rana
The bug happened because in some cases the function JOIN::exec
did not save the value of TABLE::pre_idx_push_select_cond in
TABLE::select->pre_idx_push_select_cond for the sort table.
Noticed and fixed a bug in the function make_cond_remainder
that builds the remainder condition after extraction of an index
pushdown condition from the where condition. The code
erroneously assumed that the function make_cond_for_table left
the value of ICP_COND_USES_INDEX_ONLY in sub-condition markers.
Adjusted many result files from the regression test suite
after this fix .
The call of the virtual function cancel_pushed_idx_cond in the code of
the function test_if_skip_sort_order was misplaced when backporting the
fix for bug 58816.
Better error message if --log-bin is used without --log-bin-index
mysql-test/lib/v1/mysql-test-run.pl:
Fixed that test doesn't abort if 'var' points to a deleted directory (common case when using --mem)
sql/mysqld.cc:
Better error message if --log-bin is used without --log-bin-index
- More test result updates (the errors are the same, the difference is that "at row X" became "at row Y" due to
queries with semi-joins producing select results in different order)
Analysis:
Equality propagation propagated the constant '7' into
args[0] of the Item_in_optimizer that stands for the
"< ANY" predicate. At the same the min/max subquery
rewrite swapped the order of the left and right operands
of the "<" predicate, but used Item_in_subselect::left_expr.
As a result, when the <ANY predicate is executed early in the
execution phase as a contant condition, instead of a constant
right (swapped) argument of the < predicate, there was a field
(t3.a). This field had no data, since the whole predicate is
considered constant, and it is evaluated before any tables are
read. Having junk in the field row buffer produced wrong result
Solution:
Fix create_swap to pick the correct Item_in_optimizer left
argument.
The problem was that merged views has its own nest_level numbering =>
when we compare nest levels we should take into considiration basis (i.e. 0 level),
if it is different then nest levels are not comparable.
- Make eliminate_tables_for_list() take into account that it is not possible
to eliminate a table if it is used in the upper-side ON expressions. Example:
xxx JOIN (t1 LEFT JOIN t2 ON cond ) ON func(t2.columns)
Here it would eliminate t2 which is not possible because of use of t2.columns.
- The bug was caused by the following scenario:
= a quick select is created with get_quick_select_for_ref. The quick
select refers to temporary (derived) table. It saves table->file, which
refers to a ha_heap object.
= When temp table is populated, ha_heap reaches max. size and is converted
to a ha_myisam. However, quick->file remains pointing to where ha_heap
was.
= Attempt to use the quick select causes crash.
- Fixed by introducing QUICK_SELECT_I::replace_handler(). Note that it will
not work for index_merge quick selects. Which is fine, because these
quick selects are never created for derived tables.
