SQL: Working with huge tables of chronological data

Hi,

I'm trying to figure out an efficient way to search for the non existence of events in chronological data with SQL. The goal (detailed below) seems pretty simple but so far it looks like it's tricky to do with Oracle. Here's my problem:

I'm working with 2 simple but huge tables each recording a different kind of event associated with a timestamp. For instance:

Table A
(03:50pm, A1)
(03:55pm, A2)
(03:58pm, A3)

Table B
(03:51pm, B1)
(04:00pm, B2)

I'm looking for all the chronological sequences (Ax, Ay) where no B event is present between Ax and Ay. In this example, the result would be (A2, A3).

I've been searching actively for an efficient solution for this problem and I couldn't find any fast enough. Do you have any idea?

Thanks a lot,

John Received on Thu Apr 05 2007 - 09:27:23 CDT