Re: update very slow

[james che]

Below is the output for your review, thanks

EXPLAIN SELECT * FROM scheduled_messages WHERE scheduled_time = '2012-09-12 15:00:00' AND status = 'scheduled' AND batchID IS NULL
ORDER BY aggregatorID ASC,shortcodeID ASC LIMIT 1100\G

id: 1
select_type: SIMPLE
table: scheduled_messages
type: index_merge
possible_keys: idx_time,batch
key: idx_time,batch
key_len: 9,5
ref: NULL
rows: 33835
Extra: Using intersect(idx_time,batch); Using where; Using filesort
1 row in set (0.16 sec)



mysql> SHOW STATUS LIKE 'Handler%';
+----------------------------+-------+
| Variable_name | Value |
+----------------------------+-------+
| Handler_commit | 3 |
| Handler_delete | 0 |
| Handler_discover | 0 |
| Handler_prepare | 0 |
| Handler_read_first | 0 |
| Handler_read_key | 1102 |
| Handler_read_last | 0 |
| Handler_read_next | 1375 |
| Handler_read_prev | 0 |
| Handler_read_rnd | 1100 |
| Handler_read_rnd_next | 0 |
| Handler_rollback | 0 |
| Handler_savepoint | 0 |
| Handler_savepoint_rollback | 0 |
| Handler_update | 0 |
| Handler_write | 0 |
+----------------------------+-------+
16 rows in set (0.09 sec)