In MySQL, which is more efficient: IFNULL or NULLIF? -

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these 2 mysql functions same thing:

ifnull(column_name, 'test') = 'test'

or 

nullif(column_name, 'test') null

which 1 more efficient?

they both efficient each other - functions have same overhead each other.

but more efficient either:

(column_name null   or column_name = 'test')

because function doesn't need invoked.

you may find putting more commonly encountered test first improves performance.

with questions this, simplest , more reliable way discover relative performance try them , compare query timings. make sure have production-sized , realistic-valued datasets test fair.


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