Mysql Not Returns Data But Data Are There

Question

Very strange problem today. Query as simple as basic math:

MariaDB [betradar]> select id,id_event,id_bookmaker  from event_outcome where id like '%16069689%';
+----------+----------+--------------+
| id       | id_event | id_bookmaker |
+----------+----------+--------------+
| 16069689 |    11198 |           14 |
+----------+----------+--------------+

But this one makes me crazy:

MariaDB [betradar]> select id,id_event  from event_outcome where id=16069689;
Empty set (0.00 sec)

That is: the select does not return any data although data is right there. Is this a problem related to clustered keys? My table:

 CREATE TABLE `event_outcome` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `id_event` int(11) unsigned NOT NULL,
  `id_outcome` int(11) unsigned NOT NULL,
  `id_bookmaker` int(11) unsigned NOT NULL,
  `outcome_type` varchar(50) DEFAULT NULL ,
  `quotation` decimal(10,2) NOT NULL,
  `quotation_datetime` datetime DEFAULT NULL,
  `is_last` tinyint(1) unsigned zerofill NOT NULL DEFAULT '0',
  `create_time` int(11) DEFAULT '0',
  `update_time` int(11) DEFAULT '0',
  `timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `mp_read` tinyint(4) DEFAULT '0',
  PRIMARY KEY (`id`),
  KEY `idx_event` (`id_event`),
  KEY `idx_outcome` (`id_outcome`),
  KEY `idx_bookmaker` (`id_bookmaker`),
  KEY `idx_is_last` (`is_last`),
  KEY `idx_outcome_type` (`outcome_type`),
  KEY `clstr_event` (`id_event`,`id_outcome`,`id_bookmaker`,`is_last`,`mp_read`) `clustering`=yes
) ENGINE=TokuDB AUTO_INCREMENT=16632394 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT `compression`='tokudb_zlib'

Answer 1

I don't understand your original query, why would you have a WHERE clause and match an int with a like expression?

If you want to see if the clustering index is the issue you've got two options:

• drop it, and rerun the queries
• force both queries to use the PK index with an index hint