Re: Yet Another COUNT(*)...WHERE...question

On 8/15/07, Phoenix Kiula <phoenix.kiula@gmail.com> wrote:
> I'm grappling with a lot of reporting code for our app that relies on
> queries such as:
>
>      SELECT COUNT(*) FROM TABLE WHERE ....(conditions)...
>
> And I still do not find, from the discussions on this thread, any
> truly viable solution for this. The one suggestion is to have a
> separate counts table, which is fine for total aggregates related to,
> say, an ID. E.g., a table with:
>
>     trader_id, trade_count
>
> But this is an overall count for the trader (in my example). What if I
> need a count of all his trades in the last one week. Then I need a
> timestamp condition in there as well. The number of such possibilities
> for multiple WHERE conditions is infinite...how should we account for
> all these avenues?
>
> Would love to hear experiences of others and what compromises they
> have made. From a reporting perspective, waiting for 10 minutes for a
> simple count to return seems untenable.

Generally, for these kinds of things it's often best to use
materialized views / rollup tables so that you aren't re-aggregating
the same data over and over.