What is blob,mysql blob size configuration Introduction _mysql

A blob is a large file, a typical blob is a picture or a sound file and, due to their size, must be handled in a special way (for example, uploading, downloading, or storing to a database). According to Eric Raymond, the main idea for dealing with blobs is to let the file processor (such as the database Manager) ignore what the file is, and instead care about how to handle it. However, some experts stressed that this method of dealing with large data objects is a double-edged sword, it may cause some problems, such as the storage of binary files too large, the performance of the database will be degraded. Storing large multimedia objects in a database is a typical example of application processing blobs.

MySQL blob type

In MySQL, a Blob is a series of types, including: Tinyblob, BLOBs, Mediumblob, Longblob, the only difference between these types is the maximum size of the storage file.
Four types of blob for MySQL
Type size (units: bytes)
Tinyblob Max 255
Blob Max 65K
Mediumblob Max 16M
Longblob Max 4G

Linux modification etc/my.cnf
[Mysqld]
Max_allowed_packet = 16M//differs from max_allowed_packet under [mysqldump]