main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
The bug appears because of the Item_func_in::build_clone() method.
The 'array' field for the Item_func_in item that can be pushed into
the materialized view/derived table was built in the wrong way.
It becomes lame after the pushdown of the condition into the first
SELECT that defines that view/derived table. The server crashes in
the pushdown into the next SELECT while trying to use already lame
'array' field.
To fix it Item_func_in::build_clone() was changed.
The bug appears because of the wrong pushdown into the WHERE clause of the
materialized derived table/view work. For the excl_dep_on_grouping_fields()
method that checks if the condition can be pushed into the WHERE clause
the case when Item_cond is used is missing. For Item_cond elements this
method always returns positive result (that condition can be pushed).
So this condition is pushed even if is shouldn't be pushed.
To fix it new Item_cond::excl_dep_on_grouping_fields() method is added.
Consider an IN predicate with ROW-type arguments:
predicant IN (value1, ..., valueM)
where predicant and all values consist of N elements.
When performing IN for these arguments, at every position i (1..N)
only data type of i-th element of predicant was taken into account,
while data types on i-th elements of value1..valueM were not taken.
These led to bad comparison data type detection, e.g. when
mixing unsigned and signed integer values.
After this change all element data types are taken into account.
So, for example, a mixture of unsigned and signed values is
now calculated using decimal and does not overflow any more.
Detailed changes:
1. All comparators for ROW elements are now created recursively
at fix_fields() time, inside cmp_item_row::prepare_comparators().
Previously prepare_comparators() installed comparators only
for temporal data types, while comparators for other types were
installed at execution time, in cmp_item_row::store_value().
2. Removing comparator creating code from cmp_item_row::store_value().
It was responsible for non-temporal data types.
3. Removing find_date_time_item(). It's not needed any more.
All ROW-element data types are now covered by
cmp_item_row::prepare_comparators().
4. Adding a helper method Item_args::alloc_and_extract_row_elements()
to extract elements from an array of ROW-type Items, from the given
position. Using this method to collect elements from the i-th
position and further pass them to
Type_handler_hybrid_field_type::aggregate_for_comparison().
5. Moving the call for alloc_comparators() inside
cmp_item_row::prepare_comparators(). This helps
to call prepare_comparators() for ROW elements recursively
(if elements appear to be ROWs again).
Moving alloc_comparators() from "public" to "private".
IN predicate defined with non-constant values is pushed down
The problem appears because of wrong changes made in MDEV-16090 in the
Item_func_in::build_clone() method.
For the clone of the IN predicate it copied 'cmp_fields' array values
that become dirty after Item::cleanup_excluding_const_fields_processor
has worked in pushdown. That causes crash.
There is no need to copy 'cmp_fields' field, the array values should be
NULLs in order to fix_fields() for the cloned IN predicate can set them
correctly. fix_fields() computes values for 'cmp_fields' array only
if they were not set earlier.
The problem described in the bug report happened because the code
did not test check_cols(1) after fix_fields() in a few places.
Additionally, fix_fields() could be called multiple times for SP variables,
because they are all fixed at a early stage in append_for_log().
Solution:
1. Adding a few helper methods
- fix_fields_if_needed()
- fix_fields_if_needed_for_scalar()
- fix_fields_if_needed_for_bool()
- fix_fields_if_needed_for_order_by()
and using it in many cases instead of fix_fields() where
the "fixed" status is not definitely known to be "false".
2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields()
to catch double execution.
3. Adding tests.
As a good side effect, the patch removes a lot of duplicate code (~60 lines):
if (!item->fixed &&
item->fix_fields(..) &&
item->check_cols(1))
return true;
failure upon SELECT with impossible condition
The problem appears because of a wrong implementation of the
Item_func_in::build_clone() method. It didn't clone 'array' and 'cmp_fields'
fields for the cloned IN predicate and this could cause crashes.
The Item_func_in::fix_length_and_dec() method was refactored and a new method
named Item_func_in::create_array() was created. It allowed to create 'array'
for cloned IN predicates in a proper way.
multiple times with different arguments.
If the ON expression of an outer join is an OR formula with one
of the disjunct being a constant formula then the expression
cannot be null-rejected if the constant formula is true. Otherwise
it can be null-rejected and if so the outer join can be converted
into inner join. This optimization was added in the patch for
mdev-4817. Yet the code had a defect: if the query was used in
a stored procedure with parameters and the constant item contained
some of them then the value of this constant item depended on the
values of the parameters. With some parameters it may be true,
for others not. The validity of conversion to inner join is checked
only once and it happens only for the first call of procedure.
So if the parameters in the first call allowed the conversion it
was done and next calls used the transformed query though there
could be calls whose parameters made the conversion invalid.
Fixed by cheking whether the constant disjunct in the ON expression
originally contained an SP parameter. If so the expression is not
considered as null-rejected. For this check a new item's attribute
was intruduced: Item::with_param. It is calculated for each item
by fix fields() functions.
Also moved the call of optimize_constant_subqueries() in
JOIN::optimize after the call of simplify_joins(). The reason
for this is that after the optimization introduced by the patch
for mdev-4817 simplify_joins() can use the results of execution
of non-expensive constant subqueries and this is not valid.
Modern compilers (such as GCC 8) emit warnings that the
'register' keyword is deprecated and not valid C++17.
Let us remove most use of the 'register' keyword.
Code in 'extra/' is not touched.
This patch does the following:
1. Makes Field_vers_trx_id::type_handler() return
&type_handler_vers_trx_id rather than &type_handler_longlong.
Fixes Item_func::convert_const_compared_to_int_field() to
test field_item->type_handler() against &type_handler_vers_trx_id,
instead of testing field_item->vers_trx_id().
2. Removes VERS_TRX_ID related code from
Type_handler_hybrid_field_type::aggregate_for_comparison(),
because "BIGINT UNSIGNED GENERATED ALWAYS AS ROW {START|END}"
columns behave just like a BIGINT in a regular comparison,
i.e. when not inside AS OF.
3. Removes
- Type_handler_hybrid_field_type::m_vers_trx_id;
- Type_handler_hybrid_field_type::m_flags;
because a "BIGINT UNSIGNED GENERATED ALWAYS AS ROW {START|END}"
behaves like a regular BIGINT column when in UNION.
4. Removes Field::vers_trx_id(), Item::vers_trx_id(), Item::field_flags()
They are not needed anymore. See N1.
this is a 10.3 version of 27d94b7e03
It disables caching of the first argument of IN,
if it's of a temporal type. Because other types are not
cached in this context.
reorder items in args[] array. Instead of
when1,then1,when2,then2,...[,case][,else]
sort them as
[case,]when1,when2,...,then1,then2,...[,else]
in this case all items used for comparison take a continuous part
of the array and can be aggregated directly. and all items that
can be returned take a continuous part of the array and can be
aggregated directly. Old code had to copy them to a temporary
array before aggreation, and then copy back (thd->change_item_tree)
everything that was changed.
this is a 10.3 version of bf1ca14ff3
Refactor get_datetime_value() not to create Item_cache_temporal(),
but do it always in ::fix_fields() or ::fix_length_and_dec().
Creating items at the execution time doesn't work very well with
virtual columns and check constraints that are fixed and executed
in different THDs.
