Solaris10でMySQL5.1.30を実行しています。毎月12に分割するテーブルがあるためです。
次のようなテーブル構造
mysql> desc my_events;
+-----------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+--------------+------+-----+---------+----------------+
| event_id | bigint(20) | NO | PRI | NULL | auto_increment |
| timestamp | timestamp | NO | PRI | NULL | |
| object | varchar(10) | YES | | NULL | |
| info | text | YES | | NULL | |
+-----------+--------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)
mysql> SELECT PARTITION_NAME, TABLE_ROWS, PARTITION_EXPRESSION, PARTITION_DESCRIPTION FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_SCHEMA = 'test11' AND PARTITION_METHOD = 'RANGE';
+----------------+------------+----------------------+-----------------------+
| PARTITION_NAME | TABLE_ROWS | PARTITION_EXPRESSION | PARTITION_DESCRIPTION |
+----------------+------------+----------------------+-----------------------+
| p001 | 0 | to_days(timestamp) | 733773 |
| p002 | 0 | to_days(timestamp) | 733804 |
| p003 | 20863 | to_days(timestamp) | 733832 |
| p004 | 269336 | to_days(timestamp) | 733863 |
| p005 | 3094672 | to_days(timestamp) | 733893 |
| p006 | 2639348 | to_days(timestamp) | 733924 |
| p007 | 314010 | to_days(timestamp) | 733954 |
| p008 | 0 | to_days(timestamp) | 733985 |
| p009 | 0 | to_days(timestamp) | 734016 |
| p010 | 0 | to_days(timestamp) | 734046 |
| p011 | 0 | to_days(timestamp) | 734077 |
| p012 | 0 | to_days(timestamp) | 734107 |
+----------------+------------+----------------------+-----------------------+
12 rows in set (0.05 sec)
特定の日数を照会したい場合。
mysql> DESCRIBE PARTITIONS SELECT * FROM my_events where timestamp > '2009-03-01' and timestamp < '2009-03-30';
+----+-------------+-------------------+-------------------------------------------------------------+------+---------------+------+---------+------+---------+-------------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------------------+-------------------------------------------------------------+------+---------------+------+---------+------+---------+-------------+
| 1 | SIMPLE | my_events | p001,p002,p003,p004,p005,p006,p007,p008,p009,p010,p011,p012 | ALL | NULL | NULL | NULL | NULL | 6338229 | Using where |
+----+-------------+-------------------+-------------------------------------------------------------+------+---------------+------+---------+------+---------+-------------+
1 row in set (0.01 sec)
タイムスタンプにタイプtimestampを使用すると、すべてのパーティションが照会されます。ただし、タイプをタイムスタンプの日時に変更すると、1つのパーティションのみが照会されます（p004）。
mysql> DESCRIBE PARTITIONS SELECT * FROM my_events where timestamp > '2009-03-01' and timestamp < '2009-03-30';
+----+-------------+-------------------+------------+------+---------------+------+---------+------+---------+-------------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------------------+------------+------+---------------+------+---------+------+---------+-------------+
| 1 | SIMPLE | my_events | p004 | ALL | NULL | NULL | NULL | NULL | 6338229 | Using where |
+----+-------------+-------------------+------------+------+---------------+------+---------+------+---------+-------------+
1 row in set (0.00 sec)
タイムスタンプにタイプtimestampを使用して、1つのパーティションのみをクエリするにはどうすればよいですか？