Syntax
------

BLOB[(M)]

Description
-----------

A BLOB column with a maximum length of 65,535 (216 - 1) bytes. Each BLOB value
is stored using a two-byte length prefix that indicates the number of bytes in
the value.

An optional length M can be given for this type. If this is done, MariaDB
creates the column as the smallest BLOB type large enough to hold values M
bytes long.

BLOBS can also be used to store dynamic columns.

Before MariaDB 10.2.1, BLOB and TEXT columns could not be assigned a DEFAULT
value. This restriction was lifted in MariaDB 10.2.1.

Indexing
--------

MariaDB starting with 10.4
--------------------------
From MariaDB 10.4, it is possible to set a unique index on a column that uses
the BLOB data type. In previous releases this was not possible, as the index
would only guarantee the uniqueness of a fixed number of characters.

Oracle Mode
-----------

MariaDB starting with 10.3
--------------------------
In Oracle mode from MariaDB 10.3, BLOB is a synonym for LONGBLOB.

URL: https://mariadb.com/kb/en/blob/