[ANN] V4RB mac 2.1 b13 uploaded

[Ed Kleban]

On 12/8/05 2:06 AM, "Ruslan Zasukhin" <sunshine at public.kherson.ua> wrote:

> On 12/8/05 3:37 AM, "Ed Kleban" <Ed at Kleban.com> wrote:
> 
>>> ***** NEW ******
>>> 
>>> * Added Aggregate Functions, i.e should be used with GROUP BY.
>>>     
>>>         STDDEV()
>>>         bit_and()
>>>         bit_or()
>>>         bit_xor()
>>> 
>> 
>> And presumably bit_not(x,y) and bit_count(x) as well?
>> 
>> I'm not sure how any of these other than STDDEV and possibly bit_count(x)
>> might qualify as Aggregate functions.   What does it mean to use bit_and()
>> as an aggregate?
> 
> SELECT f1, count(f1), bit_and(f1)
> FROM T 
> GROUP BY f1
> 
> 
> So everything as for other aggregate functions:
> 
> GROUP BY f1, split your table to some groups.
> Then for each group is applied function.
> 
> As I see, this is useful only for small groups, because you can easy get all
> bits ON for big groups.
> 
> And I think to use them, it needs to have SPECIAL data in table.
> 

Ok, I get it now.  This aggregation with bit_and, bit_or, and bit_xor is
across successive records in a group and is a DIFFERENT use from these three
functions as expression operators.  I was confused.  Thanks for clearing it
up.