OK I have been here several times before, and my solution
has been to split the problem in a client application, but
now that I am using PHP, that option is not practical.

Version of Firebird does not seem to matter, but I do now
have 1.5RC8 up.

Table ACTIONS has 140000 records from historic data.
ID = INTEGER PRIMARY KEY
TICKET_REF = TIMESTAMP
SERVED = INTEGER

SELECT A.TICKET_REF FROM ACTIONS A
GROUP BY A.TICKET_REF
HAVING COUNT(A.TICKET_REF) = 7

Gives a single result ( fast )
= 6 down to = 2 gives an increasing number of results with
12000 'pairs' of entries.

UPDATE ACTIONS U
SET U.SERVED = U.SERVED / 7
WHERE U.TICKET_REF IN
( SELECT A.TICKET_REF FROM ACTIONS A
GROUP BY A.TICKET_REF
HAVING COUNT(A.TICKET_REF) = 7 )

Is simple enough, hopefully you can see where I am going ( I
want to run it for 6 down to 2 as well ;) ), and I'm not too
concerned about the time it takes - except after 3 hours it
had not finished!

Now I can drop into Builder and get the result I want quite
quickly, simply by dropping the results of the first query
into a simple update. WHY can't I do that in one hit?

--
Lester Caine
-----------------------------
L.S.Caine Electronic Services