Add an index on graphs_items(graphid)

[Kioob]

Hello,

maybe it's fixed on the recent versions, but it was not on mine. On my logs I saw this "slow query" :
# Query_time: 6.187004 Lock_time: 0.000033 Rows_sent: 1 Rows_examined: 3307405
SELECT MIN(t.clock) as clock FROM graphs_items gi, trends t WHERE gi.graphid=709 AND t.itemid = gi.itemid;

So, explain return that :

+----+-------------+-------+-------+----------------+----------------+---------+-----------------+---------+-------------+
| id | select_type | table | type  | possible_keys  | key            | key_len | ref             | rows    | Extra       |
+----+-------------+-------+-------+----------------+----------------+---------+-----------------+---------+-------------+
|  1 | SIMPLE      | t     | index | PRIMARY        | PRIMARY        | 12      | NULL            | 2424217 | Using index | 
|  1 | SIMPLE      | gi    | ref   | graphs_items_1 | graphs_items_1 | 8       | zabbix.t.itemid |       1 | Using where | 
+----+-------------+-------+-------+----------------+----------------+---------+-----------------+---------+-------------+

So I add the index on graphs_items :

alter table graphs_items add index ( graphid );
Query OK, 3790 rows affected (2,18 sec)

And now the explain return that :

+----+-------------+-------+------+------------------------+---------+---------+------------------+--------+-------------+
| id | select_type | table | type | possible_keys          | key     | key_len | ref              | rows   | Extra       |
+----+-------------+-------+------+------------------------+---------+---------+------------------+--------+-------------+
|  1 | SIMPLE      | gi    | ref  | graphs_items_1,graphid | graphid | 8       | const            |      3 |             | 
|  1 | SIMPLE      | t     | ref  | PRIMARY                | PRIMARY | 8       | zabbix.gi.itemid | 132205 | Using index | 
+----+-------------+-------+------+------------------------+---------+---------+------------------+--------+-------------+

And the query is now "immediate".

PS : I use the MySQL version.

[Kioob]

If it well understand this topic, the problem is already fixed on latest version, so... sorry for noise