Performance Comparison of Oracle database date filtering methods

In the development of SQL, filter date is often encountered in the situation, how to efficiently filter out the date period? This article is validated by experiments:

Method One, compare dates into strings by To_char

To_char (cr.contractenddate, ' yyyy-mm-dd ') >= ' 2014-11-13 '
and To_char (cr.contractenddate, ' yyyy-mm-dd ') <= ' 2015-11-19 '

Time: 0.171s

Method Two, by To_date to convert the string to a date for comparison

Cr.contractenddate >= to_date (' 2014-11-13 ', ' yyyy-mm-dd ')
and Cr.contractenddate <= to_date (' 2015-11-19 ', ' yyyy-mm-dd ')

Time: 0.093s

Method Three, through the database keyword between and comparison

Cr.contractenddate
Between To_date (' 2014-11-13 ', ' yyyy-mm-dd ') and to_date (' 2015-11-19 ', ' yyyy-mm-dd ')

Time: 0.078s

Summary: Methods a time-consuming body now needs to compare each character of a string one by another;

Method two time-consuming reflected in >= and <=;

Recommended Use Method Three

Performance Comparison of Oracle database date filtering methods