这期内容当中小编将会给大家带来有关如何解决查询结果集很小但Created_tmp_disk_tables不断增加的问题，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。

创新互联公司专注于郑州企业网站建设,响应式网站设计,成都商城网站开发。郑州网站建设公司,为郑州等地区提供建站服务。全流程按需开发网站，专业设计，全程项目跟踪，创新互联公司专业和态度为您提供的服务

create table tb(id int , va varchar(10));

insert into tb(id, va) values (1, 'Created_tmp_disk_tables');

Some query conditions prevent the use of an in-memory temporary table, in which case the server uses an on-disk table instead:

Presence of a BLOB or TEXT column in the table. This includes user-defined variables having a string value because they are treated as BLOB or TEXT columns, depending on whether their value is a binary or nonbinary string, respectively.

# BLOB、TEXT列， 或者自定义变量被按BLOB、TEXT类型处理

alter table tb modify va text;

select * from (select * from tb) t;

Presence of any string column with a maximum length larger than 512 (bytes for binary strings, characters for nonbinary strings) in the SELECT list, if UNION or UNION ALL is used.

# 列长度定义超过512，在union时

alter table tb modify va varchar(513);

select * from tb union select * from tb;

The SHOW COLUMNS and DESCRIBE statements use BLOB as the type for some columns, thus the temporary table used for the results is an on-disk table.

# 查询表的列信息时。这个比较坑

SHOW columns from tb ;

DESCRIBE tb;

上述就是小编为大家分享的如何解决查询结果集很小但Created_tmp_disk_tables不断增加的问题了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注创新互联行业资讯频道。

标题名称：如何解决查询结果集很小但Created_tmp_disk_tables不断增加的问题
当前链接：http://kswjz.com/article/jjoesc.html