On Thu, Jul 10, 2008 at 02:19:30PM +0200, Ivan Sergio Borgonovo wrote: > On Thu, 10 Jul 2008 11:50:01 +0200 > Martijn van Oosterhout <kleptog@xxxxxxxxx> wrote: Hmm, I just studied your query to determine what you're trying to do. As I understand it: For each item Determine the brand Get the top three items for this brand If this item is one of them, display it This is pretty inefficient but I can't see an efficient way to do it either. I suppose one thing to try would be a multicolumn index on (brand,datainserimento) to avoid the sort step. Also, the table b1 in the original query is redundant. It's the fact that you want the top three items that makes it difficult, not sure how to deal with that. Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > Please line up in a tree and maintain the heap invariant while > boarding. Thank you for flying nlogn airlines.
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