I'm trying to find rows in a table where there have been other rows created within a minute of them.
You can't use group by for this because certain rows will exist inside of 2 groups.
timestamp minute logical group ----------------------------------------------------------- 2010-01-01 09:09:01 A1 2010-01-01 09:09:58 A1, A2 2010-01-01 09:10:02 B1, A2 2010-01-01 09:10:58 B1 2010-01-01 09:15:00 C1 2010-01-01 09:15:50 C1