Simetrical wrote:
On 9/18/06, Timwi timwi@gmx.net wrote:
Yeah, but then surely you'd have to take the union of a potentially large number of tables to display a single-category view, which I suspect is going to remain a more common request than a category-intersection view. Isn't that going to give you a substantial performance hit for large categories?
I'm not sure where you get this idea that each intersection would be a separate table. Obviously it wouldn't, it would still be one single database table, containing everything. And this single table can be queried for a single category, which (assuming proper indexes are in place) would not be any less efficient than it already is currently.
Yes, I see now. But not only the table would be larger, you would have many more indices as well,
Yeah, like, maybe 4 instead of 2.
and however you cast it you'd need to complicate queries for single-category retrieval.
Yeah, by adding the incredibly long and complex "DISTINCT" keyword and nothing else.
As to how much of a performance hit that would be, well, that's out of my league
I get the impression that it's not the only thing that's out of your league.
Timwi