LONGTEXT [CHARACTER SET charset_name] [COLLATE collation_name]
A TEXT column with a maximum length of 4,294,967,295 or 4GB (
232 - 1) characters. The effective maximum length is less if the value contains multi-byte characters. The effective maximum length of LONGTEXT columns also depends on the configured maximum packet size in the client/server protocol and available memory. Each LONGTEXT value is stored using a four-byte length prefix that indicates the number of bytes in the value.