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MDEV-26149: The test main.fetch_first fails in case it is run in PS mode
The root cause of test failure is that on optimization
of the statement clause 'order by (select 1)' in outer select
is done incorrect in case the statement run in PS mode.
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dmitryshulga committed Jul 19, 2021
1 parent 74f5aa1 commit fa45400
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Showing 3 changed files with 36 additions and 16 deletions.
@@ -1,7 +1,3 @@
if (`SELECT $PS_PROTOCOL != 0`)
{
--skip Test temporarily disabled for ps-protocol
}
--echo #
--echo # The following entries are meant for testing the parser, ensuring
--echo # the right values are passed down to the executor, for all possible
@@ -1818,6 +1818,14 @@ class Item :public Value_source,
their method implementations typically have DBUG_ASSERT(0).
*/
virtual bool is_evaluable_expression() const { return true; }

/**
* Check whether the item is a parameter ('?') of stored routine.
* Default implementation returns false. Method is overridden in the class
* Item_param where it returns true.
*/
virtual bool is_stored_routine_parameter() const { return false; }

bool check_is_evaluable_expression_or_error()
{
if (is_evaluable_expression())
@@ -4281,6 +4289,7 @@ class Item_param :public Item_basic_value,
return state == SHORT_DATA_VALUE &&
value.type_handler()->cmp_type() == INT_RESULT;
}
bool is_stored_routine_parameter() const override { return true; }
/*
This method is used to make a copy of a basic constant item when
propagating constants in the optimizer. The reason to create a new
@@ -1273,22 +1273,37 @@ Item_singlerow_subselect::select_transformer(JOIN *join)
Query_arena *arena, backup;
arena= thd->activate_stmt_arena_if_needed(&backup);

auto need_to_pull_out_item = [](enum_parsing_place context_analysis_place,
Item *item) {
return
!item->with_sum_func() &&
/*
We can't change name of Item_field or Item_ref, because it will
prevent its correct resolving, but we should save name of
removed item => we do not make optimization if top item of
list is field or reference.
TODO: solve above problem
*/
item->type() != FIELD_ITEM && item->type() != REF_ITEM &&
/*
The item can be pulled out to upper level in case it doesn't represent
the constant in the clause 'ORDER/GROUP BY (constant)'.
*/
!((item->is_order_clause_position() ||
item->is_stored_routine_parameter()) &&
(context_analysis_place == IN_ORDER_BY ||
context_analysis_place == IN_GROUP_BY)
);
};

if (!select_lex->master_unit()->is_unit_op() &&
!select_lex->table_list.elements &&
select_lex->item_list.elements == 1 &&
!select_lex->item_list.head()->with_sum_func() &&
/*
We can't change name of Item_field or Item_ref, because it will
prevent its correct resolving, but we should save name of
removed item => we do not make optimization if top item of
list is field or reference.
TODO: solve above problem
*/
!(select_lex->item_list.head()->type() == FIELD_ITEM ||
select_lex->item_list.head()->type() == REF_ITEM) &&
!join->conds && !join->having &&
thd->stmt_arena->state != Query_arena::STMT_INITIALIZED_FOR_SP
)
need_to_pull_out_item(
join->select_lex->outer_select()->context_analysis_place,
select_lex->item_list.head()) &&
thd->stmt_arena->state != Query_arena::STMT_INITIALIZED_FOR_SP)
{
have_to_be_excluded= 1;
if (thd->lex->describe)

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