SQL performance tips --- Using DATE columns

use-the-index-luke-test.sql

CREATE INDEX tbl_idx ON tbl (date_column);
SELECT text, date_column
  FROM tbl
 WHERE YEAR(date_column) = '2012';
 
# It should changes to the below: 
# Wrapping the table column in a function renders the index useless for this query.
# Write queries for continuous periods as explicit range condition:

SELECT text, date_column
  FROM tbl
 WHERE date_column >= STR_TO_DATE('2012-01-01', '%Y-%m-%d')
   AND date_column <  STR_TO_DATE('2013-01-01', '%Y-%m-%d');