CODEWITHSUNDEEP
mysqlsql
dina
dina

Reputation: 4289

sql query performance when using functions in where condition

I have the following query

select e_name 
from my_table 
where year_week between yearweek('2021-11-10') and yearweek('2021-11-18');

will the yearweek('2021-11-10') function be executed only once, before the execution, or will it be calculated for each row?

is it better to calculate it before?

select e_name 
from my_table 
where year_week between 202145 and 202146;

note: the yearweek func gets a static variable - and does not depened on the db rows

Upvotes: 1

Views: 278

Answers (1)

Bill Karwin
Bill Karwin

Reputation: 562270

https://dev.mysql.com/doc/refman/8.0/en/where-optimization.html says:

Constant expressions used by indexes are evaluated only once.

Upvotes: 2

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