Subject Re: [firebird-support] union and order by
Author Bart Smissaert
Well, it is simple, with the union and with the added between it will
use the index on that field, but with the simple or construction it
Looks like an omission in the planning code.


On 7/16/12, Svein Erling Tysvær <svein.erling.tysvaer@...> wrote:
>>Have tested and the difference is still enormous, some factor 10.
>>As predicted the added between is slightly quicker than the union
>> construction and thanks for that tip. This is in
>>fact quite useful for me as currently I have to convert a OR SQL in code
>> (VB) to the UNION and as you can imagine
>>that can be quite tricky, particularly if there is an order by. So, I will
>> change this code now to add the between
>>instead and that will be a lot simpler.
> It would be interesting to see the PLANs with the OR and UNION (and some
> information about the chosen indexes). I simply cannot remember anything
> like this with Fb 1.5.
> Set