interesting date/time query issue

I have data that is broken into anything from 30 sec to 15 minute time series (with a DATETIME field). I need to transform all of this into 15 minute data. Does anyone know off the top of their head if there a way I could use GROUP BY to make this happen? Nothing I have tried thus far has worke

Date v. DateTime index performance

If one has a large number of records per month and normally searches for things by month, yet needs to keep things time coded, does anyone know if it make sense to use datetime or separate date and a time columns? Thanks, Tom -- MySQL General Mailing List For list archives: http://lists.mysql.c