BLOB
Syntax
BLOB[(M)]
Contents
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
In 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.