in 慢查询问题

[bs7729]

CREATE TABLE IF NOT EXISTS node.travelrecord_qq (
id bigint NOT NULL AUTO_INCREMENT,
user_id varchar(100) DEFAULT NULL,
traveldate date DEFAULT NULL,
fee decimal(10, 0) DEFAULT NULL,
days int DEFAULT NULL,
blob longblob,
PRIMARY KEY (id),
KEY id (id),
KEY dex_user_id (user_id)
) ENGINE = InnoDB CHARSET = utf8
DBPARTITION BY mod_hash(user_id) DBPARTITIONS 10
TBPARTITION BY mod_hash(id) TBPARTITIONS 2;

用user_id做为分库

SELECT COUNT(1) from travelrecord_qq WHERE user_id in(28)
SELECT COUNT(1) from travelrecord_qq WHERE user_id in(18);
方式查询快

SELECT COUNT(1) from travelrecord_qq WHERE user_id in(18,28);
in里多个值后查询很慢

查询对比如下：

in有多个值时，用explain查看，把所有库与所有库都用union all 连接了

[junwen12221]

http://dl.mycat.org.cn/2.0/1.22-release/mycat2-1.22-release-jar-with-dependencies-2022-5-19.jar