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Fixed numerous problems for mutually recursive CTE.

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Actually mutually recursive CTE were not functional. Now the code
for mutually recursive CTE looks like functional, but still needs
re-writing.
Added many new test cases for mutually recursive CTE.
This commit is contained in:
Igor Babaev
2016-06-06 10:01:16 -07:00
parent 6c6c3af6aa
commit 0a6e6d705b
8 changed files with 653 additions and 32 deletions
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64
sql/sql_union.cc
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@ -244,6 +244,7 @@ select_union_recursive::create_result_table(THD *thd_arg,
if (rec_tables.push_back(rec_table))
return true;
rec_table->is_rec_table= true;
return false;
}
@ -494,7 +495,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
/* Global option */
if (is_union_select)
if (is_union_select || is_recursive)
{
if (is_union() && !union_needs_tmp_table())
{
@ -530,7 +531,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
sl->context.resolve_in_select_list= TRUE;
for (;sl; sl= sl->next_select())
{
{
bool can_skip_order_by;
sl->options|= SELECT_NO_UNLOCK;
JOIN *join= new JOIN(thd_arg, sl->item_list,
@ -587,7 +588,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
Use items list of underlaid select for derived tables to preserve
information about fields lengths and exact types
*/
if (!is_union_select)
if (!is_union_select && !is_recursive)
types= first_sl->item_list;
else if (sl == first_sl)
{
@ -917,8 +918,9 @@ bool st_select_lex_unit::exec()
bool first_execution= !executed;
DBUG_ENTER("st_select_lex_unit::exec");
bool was_executed= executed;
bool is_recursive= with_element && with_element->is_recursive;
if (executed && !uncacheable && !describe)
if (executed && !uncacheable && !describe && !is_recursive)
DBUG_RETURN(FALSE);
executed= 1;
if (!(uncacheable & ~UNCACHEABLE_EXPLAIN) && item)
@ -934,7 +936,7 @@ bool st_select_lex_unit::exec()
if (saved_error)
DBUG_RETURN(saved_error);
if (with_element && with_element->is_recursive && !describe)
if (is_recursive && !describe)
{
saved_error= exec_recursive();
DBUG_RETURN(saved_error);
@ -1174,10 +1176,7 @@ bool st_select_lex_unit::exec_recursive()
TABLE *result_table= with_element->result_table;
ha_rows examined_rows= 0;
bool unrestricted= with_element->is_unrestricted();
bool no_more_iterations= false;
bool with_anchor= with_element->with_anchor;
st_select_lex *first_sl= first_select();
st_select_lex *barrier= with_anchor ? first_recursive_sel : NULL;
uint max_level= thd->variables.max_recursion_level;
List_iterator_fast<TABLE> li(with_element->rec_result->rec_tables);
TABLE *rec_table;
@ -1186,9 +1185,31 @@ bool st_select_lex_unit::exec_recursive()
do
{
st_select_lex *first_sl;
st_select_lex *barrier;
if ((saved_error= incr_table->file->ha_delete_all_rows()))
goto err;
if (with_element->no_driving_recursive_is_set())
with_element->set_as_driving_recursive();
if (with_element->level == 0)
{
first_sl= first_select();
if (with_anchor)
barrier= first_recursive_sel;
else
barrier= NULL;
}
else
{
first_sl= first_recursive_sel;
barrier= NULL;
}
if (with_element->all_incr_are_ready())
with_element->cleanup_incr_ready();
for (st_select_lex *sl= first_sl ; sl != barrier; sl= sl->next_select())
{
thd->lex->current_select= sl;
@ -1211,16 +1232,12 @@ bool st_select_lex_unit::exec_recursive()
}
}
if (with_element->level == 0)
{
first_sl= first_recursive_sel;
barrier= NULL;
}
with_element->set_as_incr_ready();
incr_table->file->info(HA_STATUS_VARIABLE);
if (incr_table->file->stats.records == 0 ||
with_element->level + 1 == max_level)
no_more_iterations= true;
with_element->set_as_stabilized();
else
with_element->level++;
@ -1231,12 +1248,21 @@ bool st_select_lex_unit::exec_recursive()
!unrestricted)))
goto err;
}
} while (!no_more_iterations);
if (!with_element->is_driving_recursive())
break;
if ((saved_error= table->insert_all_rows_into(thd,
result_table,
true)))
goto err;
} while (!with_element->all_are_stabilized());
if (with_element->is_driving_recursive())
{
TABLE *table= with_element->rec_result->table;
if ((saved_error= table->insert_all_rows_into(thd,
result_table,
true)))
goto err;
with_element->cleanup_driving_recursive();
}
thd->lex->current_select= lex_select_save;
err: