Re: counting rows

> "Tony Andrews" <andrewst_at_onetel.com> wrote in message
> news:1143891453.767287.295100_at_i39g2000cwa.googlegroups.com...
> > Tony Rogerson wrote:
> >> Number 2 will be best because you are effectively storing the aggregate
> >> instead of the server having to count the number of rows in the table
> >> which
> >> would require IO.
> >
> > That is wildly simplistic. Based on that advice, it would be "best" to
> > always store the count, sum, min, max, avg, etc. of everything in its
> > parent table(s). Please tell me you don't!?

> Tony Rogerson wrote:
> When somebody asks this...
>
> >>Consider the tables USERS and PICTURES. When retrieving the number of
> >>pictures from a user there are two ways:
>
> >>1) I count them from pictures table.
> >>2) I pick it directly from a field "numPictures" in table users.
>
> >>How are you used to do this? Which is better?
>
> I give an answer to THAT question and not add in other stuff, if the OP
> wanted min, max, sum etc... then I'd answer differently.

So I guess what you are saying is: given that there IS a column called numPictures in table Users anyway, it is best to use it. You are not suggesting that such a column should generally be created and maintained, which is what I inferred from your answer? Received on Sun Apr 02 2006 - 12:57:03 CEST