MySQL Enum performance advantage?

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鱼传尺愫
鱼传尺愫 2020-11-29 04:06

Is there a performance advantage to using enum in situations where there are only 5-10 different possible values for a field? if not what is the advantage?

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  •  攒了一身酷
    2020-11-29 04:24

    There is a huge performance penalty to using ENUM for operations such as:

    • Query the list of permitted values in the ENUM, for instance to populate a drop-down menu. You have to query the data type from INFORMATION_SCHEMA, and parse the list out of a BLOB field returned.

    • Alter the set of permitted values. It requires an ALTER TABLE statement, which locks the table and may do a restructure.

    I'm not a fan of MySQL's ENUM. I prefer to use lookup tables. See also my answer to "How to handle enumerations without enum fields in a database?"

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