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I need to find all records created in a given year from a MySQL database. Is there any way that one of the following would be slower than the other?
WHERE create_date BETWEEN '2009-01-01 00:00:00' AND '2009-12-31 23:59:59'
or
WHERE YEAR(create_date) = '2009'
Whenever you use a function against a column, it must perform the function on every row in order to see if it matches the constant. This prevents the use of an index.
The basic rule of thumb, then, is to avoid using functions on the left side of the comparison.
Sargable means that the DBMS can use an index. Use a column on the left side and a constant on the right side to allow the DBMS to utilize an index.
Even if you don’t have an index on the create_date column, there is still overhead on the DBMS to run the YEAR() function for each row. So, no matter what, the first method is most likely faster.