indexing - Do mysql update queries benefit from an index? -

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i have table updates , i'm wondering if update queries benefit having index on column , updated column or index on column?

just on column. index on update column slow down query because index has updated along data. index on column speed updates, , selects, slow down insertions.

indices cause overhead when delete rows. in general thing though on columns using where on lot, , necessary on columns joins on, or order by


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