I have a Firebird database (1.5) that serves as the data store for the
IPCheck server monitoring application. We upload the log table
(IPCLOG) from Firebird to MSSQL so we can perform data analysis and
reporting. The log table typically contains ~30 million records.
We've been experiencing extremely slow performance on the upload, so we
decided to attempt to delete older records prior to the upload.

Using the FlameRobin interface to our Firebird instance, I entered a
simple query:

SELECT datetime FROM IPCLOG WHERE datetime < '05/01/2007'

This query takes over 1.5 hours to run. There is an index on the
datetime field, and the statistics have been updated. Is there
anything else I can do to improve this abysmal performance?

TIA for your time and expertise.