RE: Select slow with ORDER BY ... DESC

* Eldon Ziegler > > mysql is slow when finding the last value before a period of time (I'm > plotting the temperature values during a period of time and want the last > value before the period begins). > > The query is: > select DateTime, Target, Value from log >where DateTime < "2001-12-21 00

Select slow with ORDER BY ... DESC

mysql is slow when finding the last value before a period of time (I'm plotting the temperature values during a period of time and want the last value before the period begins). The query is: select DateTime, Target, Value from log where DateTime < "2001-12-21 00:00:00" and Source = "S