SELECT DISTINCT or array_unique?

Question

What do you think is faster?

SELECT DISTINCT(user_id) FROM myTable;

Then fetch to $myArray.

Or

SELECT user_id FROM myTable;

Then fetch to $myArray and do

$myArray = array_unique($myArray);

Note: user_id is a FOREIGN KEY CONSTRAINT

MatthewJ · Accepted Answer · 2013-10-20 04:20:25Z

6

For speed and memory efficiency, you want to return the minimum amount from the database without putting unnecessary rows for processing/memory efficiency. So, the distinct in this case is the better choice.

answered Oct 20, 2013 at 4:20

MatthewJ

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1 Comment

allejo Over a year ago

+1 As a rule of thumb, if MySQL can do it, it's typically faster and more efficient.

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