in Field_iterator_table::create_item
When IN predicate is converted to IN subquery we have to ensure that
any item from the select list of the subquery has some name and this name
is unique across the select list.
This was not guaranteed by the code before the patch for MDEV-17222.
If the name of an item of the select list was not set, and this happened
for binary constants, then the server crashed. If the first row in the IN
list contained the same constant in two different positions then the server
returned an error message.
This was fixed by providing all constants in the first row of the IN list
with generated names.
elements of BIGINT or YEAR type in the IN list reaches in_predicate_conversion_threshold
The bug appears at the prepare stage when IN-predicate with the long list
of values is converted into IN-subquery. It happens because values in the
right operand of the IN-predicate that have BIGINT or YEAR types are converted
into the Item_int_with_ref.
To fix it in the procedure Item_func_in::create_value_list_for_tvc
real_item() is taken for each value in the right operand of the IN-predicate.
Most "new" failures fixed in the following files:
- sql_select.cc
- item.cc
- item_func.cc
- opt_subselect.cc
Other things:
- Allocate udf_handler strings in mem_root
- Required changes in sql_string.h
- Add mem_root as argument to some new [] calls
- Mark udf_handler strings as thread specific
- Removed some comment blocks with code
Conversion of NOT IN predicates into NOT IN subqueries did not work
correctly: the predicates actually were converted into IN subqueries.
As a result if the conversion was applied for the query with
a NOT IN predicate the query could return a wrong result set.
As a result of this merge the code for the following tasks appears in 10.3:
- MDEV-12172 Implement tables specified by table value constructors
- MDEV-12176 Transform [NOT] IN predicate with long list of values INTO
[NOT] IN subquery.
TVC can be used in UNION-statement, in view and in subquery.
Files where TVC is defined and its methods are stored added.
Methods exec and prepare for TVC added.
Tests for TVC added.
