> Thank you for the quick reply..^_^
>
> But is there any way I can shink the db(other than back and restore
> it) or force it to reuse the free space?
>
> My real problem is that my program have do a lot of calculation and I
> use db as a drawing borad. If I use the ordinary harddisk to run it,
> then it will take about 2~3 week to finish one cycle of pattern
> analyzing, which is too slow. So I put the database file on a
> ramdisk,can refer to http://www.superspeed.com/servers/ramdisk.php.
> It really speed it up, but just eat up too much memory.
>
> Is gfix -sweep can use here? I try it, but seens no effect at all(may
> be is my misunderstanding the use of it).
>
> Best Reguard
>
> Allen
>

to be honest I don't think FB is a good candidate for this task.
You can improve performance by using the embedded server over the full
server if your task is single user based (which it smells that it is)
but huge quantities of inserts/deletes in a short time will alway produce
bloat which cannot be eliminated outside a backup/restore cycle
Alan