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MDEV-36486 Optimizer hints are resolved against the INSERT part of INSERT..SELECT

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When processing queries like
  INSERT INTO t1 (..) SELECT .. FROM t1, t2 ...,

there is a single query block (i.e., a single SELECT_LEX) for both INSERT and
SELECT parts. During hints resolution, when hints are attached to particular
TABLE_LIST's, the search is performed by table name across the whole
query block.
So, if a table mentioned in an optimizer hint is present in the INSERT part,
the hint is attached to the that table. This is obviously wrong as
optimizer hints are supposed to only affect the SELECT part of
an INSERT..SELECT clause.

This commit disables possible attaching hints to tables in the INSERT part
and fixes some other bugs related to INSERT..SELECT statements processing
This commit is contained in:
Oleg Smirnov
2025-04-08 16:59:28 +07:00
parent b89a1e7f35
commit fa929a2be6
12 changed files with 150 additions and 37 deletions
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46
sql/sql_base.cc
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@@ -8229,7 +8229,6 @@ void make_leaves_list(THD *thd, List<TABLE_LIST> &list, TABLE_LIST *tables,
refresh It is only refresh for subquery
select_insert It is SELECT ... INSERT command
full_table_list a parameter to pass to the make_leaves_list function
resolve_opt_hints Whether optimizer hints must be resolved here
NOTE
Check also that the 'used keys' and 'ignored keys' exists and set up the
@@ -8249,7 +8248,7 @@ void make_leaves_list(THD *thd, List<TABLE_LIST> &list, TABLE_LIST *tables,
bool setup_tables(THD *thd, Name_resolution_context *context,
List<TABLE_LIST> *from_clause, TABLE_LIST *tables,
List<TABLE_LIST> &leaves, bool select_insert,
bool full_table_list, bool resolve_opt_hints)
bool full_table_list)
{
uint tablenr= 0;
List_iterator<TABLE_LIST> ti(leaves);
@@ -8285,18 +8284,23 @@ bool setup_tables(THD *thd, Name_resolution_context *context,
leaves.push_back(table_list, thd->mem_root);
}
bool is_insert_tables_num_set= false;
/*
This variable is only used for INSERT..SELECT's:
true: processing the INSERT part of an INSERT..SELECT
false: processing the SELECT part of it
*/
bool is_insert_part= true;
while ((table_list= ti++))
{
TABLE *table= table_list->table;
if (table && !table->pos_in_table_list)
table->pos_in_table_list= table_list;
if (select_insert && !is_insert_tables_num_set &&
if (select_insert && is_insert_part &&
table_list->top_table() == first_select_table)
{
/* new counting for SELECT of INSERT ... SELECT command */
thd->lex->first_select_lex()->insert_tables= tablenr;
is_insert_tables_num_set= true;
is_insert_part= false;
tablenr= 0;
}
if(table_list->jtbm_subselect)
@@ -8321,15 +8325,22 @@ bool setup_tables(THD *thd, Name_resolution_context *context,
DBUG_RETURN(1);
}
if (qb_hints && // QB hints initialized
!table_list->opt_hints_table) // Table hints are not adjusted yet
/*
Conditions to meet for optimizer hints resolution:
(1) QB hints initialized
(2) Table hints are not adjusted yet
(3) Table is not in the INSERT part of INSERT..SELECT
*/
if (qb_hints && // (1)
!table_list->opt_hints_table && // (2)
!(select_insert && is_insert_part)) // (3)
{
table_list->opt_hints_table=
qb_hints->fix_hints_for_table(table_list->table,
table_list->alias);
}
}
if (select_insert && !is_insert_tables_num_set)
if (select_insert && is_insert_part)
{
/*
This happens for statements like `INSERT INTO t1 SELECT 1`,
@@ -8396,19 +8407,6 @@ bool setup_tables(THD *thd, Name_resolution_context *context,
if (setup_natural_join_row_types(thd, from_clause, context))
DBUG_RETURN(1);
if (resolve_opt_hints)
{
if (thd->lex->opt_hints_global && select_lex->select_number == 1)
{
thd->lex->opt_hints_global->fix_hint(thd);
/*
There's no need to call opt_hints_global->check_unresolved(),
this is done for each query block individually
*/
}
if (qb_hints)
qb_hints->check_unfixed(thd);
}
DBUG_RETURN(0);
}
@@ -8428,7 +8426,6 @@ bool setup_tables(THD *thd, Name_resolution_context *context,
select_insert It is SELECT ... INSERT command
want_access what access is needed
full_table_list a parameter to pass to the make_leaves_list function
resolve_opt_hints Whether optimizer hints must be resolved here
NOTE
a wrapper for check_tables that will also check the resulting
@@ -8445,13 +8442,12 @@ bool setup_tables_and_check_access(THD *thd, Name_resolution_context *context,
bool select_insert,
privilege_t want_access_first,
privilege_t want_access,
bool full_table_list,
bool resolve_opt_hints)
bool full_table_list)
{
DBUG_ENTER("setup_tables_and_check_access");
if (setup_tables(thd, context, from_clause, tables,
leaves, select_insert, full_table_list, resolve_opt_hints))
leaves, select_insert, full_table_list))
DBUG_RETURN(TRUE);
List_iterator<TABLE_LIST> ti(leaves);