Round Dates Every 15 Minutes?

Question

I need a way to round a date to 5 or 15 minute intervals for a query in a realtime graph. I know using the round function I can round to 1 minute or 1 hour, but I need something in the middle. Any ideas?

Answer 1

I would bet myone is faster!
SQL> select d, count(*) from t19
group by d;
D                     COUNT(*)
23.05.2005 09:20:55     999999
Elapsed: 00:00:01.19
SQL> select date '2000-01-01' + round( (d-date '2000-01-01')*24*4)/4/24, count(*)
from t19
group by date '2000-01-01' + round( (d-date '2000-01-01')*24*4)/4/24;
DATE'2000-01-01'+RO   COUNT(*)
23.05.2005 09:15:00     999999
Elapsed: 00:00:13.46
SQL> select
to_char(d + (abs(mod(to_number(to_char(d,'mi')),15) - 15)/1440),'dd/mm/rrrr hh24:mi')
, count(*)
from t19
group by
to_char(d + (abs(mod(to_number(to_char(d,'mi')),15) - 15)/1440),'dd/mm/rrrr hh24:mi');
TO_CHAR(D+(ABS(M   COUNT(*)
23/05/2005 09:30     999999
Elapsed: 00:00:14.61But I am convinced you can do faster than my one. Also note that you can use trunc(), round(), ceil(), up to you.