> This application is a Delphi app accessing the Firebird database
> directly over the Internet via the BDE.

BDE!!! over the Internet!!!
I'm sorry but you are never going to get good (read acceptable) performancce
over the internet. The bandwidth is just not up to it. Even tunnelling under
compression is not going to work, since the transport protocol of FB is
small/numerous packets... i's a non-starter I'm afraid.
Alan

>
> Even with FB 1.5.3 we're getting very slow responses to all the
> queries, although individually they're running extremely quickly now on
> the server itself. Having put the new server in with FB 1.5.3, the Big
> Query I referred to yesterday now takes 3 seconds to come back - a big
> improvement!
>
> It seems that while individual queries are now restored to normality, a
> barrage of short "one row" queries really drags it all down to a crawl.
> Yet when the server is on a local WAN, it all really flies with v1.5.3.
>
> I'm mystified!
>
> Trevor