database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-27 18:02:13 +03:00
Code Activity

MDEV-18479 Complement

Browse Source 
This patch complements the patch that fixes bug MDEV-18479.
This patch takes care of possible overflow when calculating the
estimated number of rows in a materialized derived table / view.
This commit is contained in:
Igor Babaev
2019-05-28 23:26:36 -07:00
parent eb09580b67
commit cbb90f77cd
5 changed files with 29 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
sql/sql_select.cc
View File

@ -3830,7 +3830,7 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
DBUG_RETURN(TRUE); /* purecov: inspected */
{
ha_rows records= 1;
double records= 1;
SELECT_LEX_UNIT *unit= join->select_lex->master_unit();
/* Find an optimal join order of the non-constant tables. */
@ -3855,10 +3855,14 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
table/view.
*/
for (i= 0; i < join->table_count ; i++)
records*= join->best_positions[i].records_read ?
(ha_rows)join->best_positions[i].records_read : 1;
set_if_smaller(records, unit->select_limit_cnt);
join->select_lex->increase_derived_records(records);
{
records= COST_MULT(records,
join->best_positions[i].records_read ?
join->best_positions[i].records_read : 1);
}
ha_rows rows= records > HA_ROWS_MAX ? HA_ROWS_MAX : (ha_rows) records;
set_if_smaller(rows, unit->select_limit_cnt);
join->select_lex->increase_derived_records(rows);
}
}
@ -10795,7 +10799,7 @@ ha_rows JOIN_TAB::get_examined_rows()
}
}
else
examined_rows= (ha_rows) records_read;
examined_rows= (ha_rows) records_read;
return examined_rows;
}
@ -22924,8 +22928,9 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
else
{
ha_rows examined_rows= tab->get_examined_rows();
item_list.push_back(new Item_int((longlong) (ulonglong) examined_rows,
ha_rows displ_rows= examined_rows;
set_if_smaller(displ_rows, HA_ROWS_MAX/2);
item_list.push_back(new Item_int((longlong) (ulonglong) displ_rows,
MY_INT64_NUM_DECIMAL_DIGITS));
/* Add "filtered" field to item_list. */