A problem in software design...

According to the BBC:
The head of the Prison Service admits he does not know how many inmates are on the run from open jails. - but according to an interview this morning he CAN tell if a given inmate is.

So, basically, he has a system which allows him to do
SELECT absconded FROM prisoners WHERE prisoner_id=NNNN
but not
SELECT count(*) FROM prisoners WHERE absconded='yes'

Ho hum.

[Edit: yes, it's a gross oversimplification. The problem is actually that there is no central database he can do either SELECT on!]