Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Won't Fix
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5.5(EOL), 10.0(EOL), 10.1(EOL), 10.2(EOL)
Description
RFC 3339 (RFC3339 time) times are not handled consistently, and specifically when it comes to partition pruning.
For reference, more on RFC 3339 can be found here:
https://www.ietf.org/rfc/rfc3339.txt
A normal datetime looks like:
2016-12-12 11:10:09
A RFC 3339 time might look like:
2016-12-14T11:09:09-05:00
The main problem I see right now is with partition pruning, but perhaps it applies to other areas.
Test case:
DROP TABLE IF EXISTS t1;
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CREATE TABLE `t1` (
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`id` int,
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`GMTDataTime` datetime NOT NULL,
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PRIMARY KEY (`GMTDataTime`,`id`),
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KEY `id` (`id`)
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) ENGINE=InnoDB DEFAULT CHARSET=latin1
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PARTITION BY LIST ( TO_DAYS(GMTDataTime))
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(PARTITION p1 VALUES IN (736673),
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PARTITION p2 VALUES IN (736674),
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PARTITION p3 VALUES IN (736675));
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INSERT INTO `t1` VALUES (1,'2016-12-10 10:10:10');
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INSERT INTO `t1` VALUES (2,'2016-12-11 11:11:11');
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INSERT INTO `t1` VALUES (3,'2016-12-12 12:12:12');
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SELECT * FROM `t1`;
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EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN '2016-12-10 10:10:10' AND '2016-12-11 11:11:11';
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EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN '2016-12-10T10:10:10-05:00' AND '2016-12-11T11:11:11-05:00';
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Note how the latter, using RFC 3339 time, does not use partition pruning (it should have excluded "p3" in "partitions" column):
mysql> EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN '2016-12-10 10:10:10' AND '2016-12-11 11:11:11';
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| 1 | SIMPLE | t1 | p1,p2 | index | PRIMARY | PRIMARY | 9 | NULL | 2 | Using where; Using index |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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1 row in set (0.00 sec)
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mysql> EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN '2016-12-10T10:10:10-05:00' AND '2016-12-11T11:11:11-05:00';
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| 1 | SIMPLE | t1 | p1,p2,p3 | index | PRIMARY | PRIMARY | 9 | NULL | 3 | Using where; Using index |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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1 row in set (0.00 sec)
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There are a couple of hacky work-arounds where you essentially re-convert the RFC 3339 time to a 'typical' datetime, which back allows partition pruning to take place:
mysql> EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN DATE_FORMAT('2016-12-10T10:10:10-05:00','%Y-%m-%d %H:%i:%s') AND DATE_FORMAT('2016-12-11T11:11:11-05:00','%Y-%m-%d %H:%i:%s');
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| 1 | SIMPLE | t1 | p1,p2 | index | PRIMARY | PRIMARY | 9 | NULL | 2 | Using where; Using index |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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1 row in set, 6 warnings (0.00 sec)
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mysql> EXPLAIN PARTITIONS SELECT * FROM `t1` WHERE `GMTDataTime` BETWEEN FROM_UNIXTIME(UNIX_TIMESTAMP('2016-12-10T10:10:10-05:00')) AND FROM_UNIXTIME(UNIX_TIMESTAMP('2016-12-11T11:11:11-05:00'));
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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| 1 | SIMPLE | t1 | p1,p2 | index | PRIMARY | PRIMARY | 9 | NULL | 2 | Using where; Using index |
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+------+-------------+-------+------------+-------+---------------+---------+---------+------+------+--------------------------+
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1 row in set, 6 warnings (0.00 sec)
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But this is quite hacky, not always possible for queries on-the-fly, and still returns [many] warnings.