mysql> select count(*) from log l, logtext lt where l.itemid=lt.itemid and year=2001 and month=2 and day=28 and logtime > '2001-02-28 10:30:00' and lt.event like '%earthquake%';
+----------+
| count(*) |
+----------+
| 279 |
+----------+
1 row in set (2.52 sec)