MySQL TEXT vs BLOB vs CLOB

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臣服心动
臣服心动 2020-11-28 07:06

What are the differences, advantages and disadvantages of these different data-types both from a performance standpoint as well as a usability standpoint?

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  • 2020-11-28 07:58

    TEXT is a data-type for text based input. On the other hand, you have BLOB and CLOB which are more suitable for data storage (images, etc) due to their larger capacity limits (4GB for example).

    As for the difference between BLOB and CLOB, I believe CLOB has character encoding associated with it, which implies it can be suited well for very large amounts of text.

    BLOB and CLOB data can take a long time to retrieve, relative to how quick data from a TEXT field can be retrieved. So, use only what you need.

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  • 2020-11-28 08:06

    It's worth to mention that CLOB / BLOB data types and their sizes are supported by MySQL 5.0+, so you can choose the proper data type for your need.

    http://dev.mysql.com/doc/refman/5.7/en/storage-requirements.html

    Data Type   Date Type   Storage Required
    (CLOB)      (BLOB)
    
    TINYTEXT    TINYBLOB    L + 1 bytes, where L < 2**8  (255)
    TEXT        BLOB        L + 2 bytes, where L < 2**16 (64 K)
    MEDIUMTEXT  MEDIUMBLOB  L + 3 bytes, where L < 2**24 (16 MB)
    LONGTEXT    LONGBLOB    L + 4 bytes, where L < 2**32 (4 GB)
    
    where L stands for the byte length of a string
    
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