>Why would I want a compound index?

That all depends on the volume and distribution of your data (e.g. if you
had thousands of records with the same room and thousands of records with
the same applet, but only a handful with the same combination, then a
compound index could be preferable), but if you get subsecond response I
agree there is no need for anything like that.

>ROOMSTAT.TAG is Indexed along with TICKET_REF, but no
>compound indexes.

>Gives it's results in sub second time. Calling it ( and the
>matching two ) 5 times gives me the information in seconds.
>It is only when it gets put together in one query it takes
>hours,

I don't understand why it takes so long, but if you told us what PLANs FB
chose to use, we might gain some new insight (e.g. do a prepare in IB_SQL),

Set