Hi,
Forgot to mention two minor details
On 02/21/11 03:17 PM, Evgeny Potemkin wrote:
...
> === modified file 'sql/item_subselect.cc'
> --- a/sql/item_subselect.cc 2011-02-18 10:46:59 +0000
> +++ b/sql/item_subselect.cc 2011-02-21 14:17:57 +0000
> @@ -2370,12 +2370,27 @@ int subselect_single_select_engine::exec
> Make sure that save_read_first_record usage doesn't
> intersect with join_materialize_table()'s.
> */
I am not sure the above comment is necessary anymore. If you want to
keep it, I think it should come after the comment below.
> - DBUG_ASSERT(!tab->save_read_first_record);
> /* Change the access method to full table scan */
> - tab->save_read_first_record= tab->read_first_record;
> + if (tab->save_read_first_record.elements)
Since elements is an int, I prefer
if (tab->save_read_first_record.elements > 0)
> + {
> + TABLE_LIST *tl= tab->table->pos_in_table_list;
> + /*
> + This is a materializable derived table and it's not
> + materialized yet.
> + */
> + DBUG_ASSERT(tl->uses_materialization()&&
> !tl->materialized);
> + // Preserve join_materialize_table to be the first handler
> + tab->save_read_first_record.push_front(
> + (READ_RECORD::Setup_func*)read_first_record_seq);
> + }
> + else
> + {
> + tab->save_read_first_record.push_front(
> + (READ_RECORD::Setup_func*)tab->read_first_record);
> + tab->read_first_record= read_first_record_seq;
> + }
> tab->save_read_record= tab->read_record.read_record;
> tab->read_record.read_record= rr_sequential;
> - tab->read_first_record= read_first_record_seq;
> tab->read_record.record= tab->table->record[0];
> tab->read_record.thd= join->thd;
> tab->read_record.ref_length=
> tab->table->file->ref_length;
> @@ -2396,9 +2411,10 @@ int subselect_single_select_engine::exec
> JOIN_TAB *tab= *ptab;
> tab->read_record.record= 0;
> tab->read_record.ref_length= 0;
> - tab->read_first_record= tab->save_read_first_record;
> + DBUG_ASSERT(tab->save_read_first_record.elements);
or DBUG_ASSERT(tab->save_read_first_record.elements > 0);
> + tab->read_first_record=
> + (READ_RECORD::Setup_func)tab->save_read_first_record.pop();
> tab->read_record.read_record= tab->save_read_record;
> - tab->save_read_first_record= NULL;
> }
> executed= true;
>
...
--
Øystein
