Re: SEVEN cross joins?!?!?
От | Stewart Ben (RBAU/EQS4) * |
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Тема | Re: SEVEN cross joins?!?!? |
Дата | |
Msg-id | E253BDD7F008244585AEE87AF8F0224F116C7ACB@cl-mail01.au.bosch.com обсуждение исходный текст |
Ответ на | SEVEN cross joins?!?!? (Frank Bax <fbax@sympatico.ca>) |
Список | pgsql-sql |
> Splitting locations into subsets (like 2,2,3) doesn't work > because it is possible that low values in one location can be offset by > high values in another location, and still result in an excellent combo. > > The good news is these suggestions got me thinking outside > the box. I think I can program a modified brute-force that bypasses > large numbers of combos early. It might still be too large/slow, so I'd be > interested in finding more info about these "smarter algorithms" in option Could you define an view with a calculated field, say, 2 * a1 + 6 * a2 + 3 * a3, and then use this aggregate to score the individual rows? I haven't looked at the exact nature of the problem, but if you're multiplying a table by itself, it may be worth redefining the problem in terms of a simple ranking algorithm, define a column to calculate this, then sort by that column. Best regards, Ben Stewart -- Robert Bosch (Australia) Pty. Ltd. Engineering Quality Services, Student Software Engineer (RBAU/EQS4) Locked Bag 66 - Clayton South, VIC 3169 - AUSTRALIA Tel: +61 3 9541-7002 Fax: +61 3 9541-7700 mailto:ben.stewart@au.bosch.com http://www.bosch.com.au/
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