>On 04/19/2014 06:26 AM, Ron Pasch wrote:
>> > - It should be possible to search for products and provide properties
>> > that the product SHOULD have, not must have.
>>>
>>> I don't understand this. Say you have a sprocket in red and green. Do you
>>> want to search for:
>>>
>>> select * from product where name = 'sprocket' and (color = 'red' or color =
>>> 'green')
>>>
>>> Or do you want something else? Does the user say they'd "prefer" blue, but
>>> will take whatever else you have?
>>>
>>> Do you search for some properties exactly and some "preferred"?
>>>
>>> Perhaps you could describe a little more how you want to query the
>>> database? Or, maybe, what your user's are searching for?
>>>
>>> -Andy
>>>
>>
>> Yes, the user can prefer certain properties and the products that match most
>> of the properties should be in the top of the results, but if a product
>> doesn't match all of them but just some of them, they should still be
>> returned, but lower in the results.
>>
>> I'm seriously wondering if doing this solely with postgres is even possible
>> without having long execution times. I've done some tests with 5 million
>> records and just doing the "or" construction you mentioned above, which
>> resulted in 600 to 900 ms queries and returning only those records of which
>> all properties match at least one selected value.
I don't think that OR clauses are the right way as the aim is to count how
many attributes do match the search.
basically a standard approach would look like:
SELECT pID, sum(match) as matches FROM
(
selct pID, 1 as match from Products where color ='pink'
UNION ALL
selct pID, 1 as match from Products where size ='XXL'
...
)foo
GROUP BY pID order by matches DESC
How many distinct attributes are involved ? ( 15 colors + 9 sizes + ....)
Marc
>>
>> I was thinking that perhaps using a search engine like lucene or sphinx
>> would be more appropriate, but then I wonder what I would exactly be
>> indexing and how I would be querying that, but that's a question for a
>> different mailing list ;-)
>
>Please keep the list cc'd, so others can help as well.
>
>Yeah, doing a bunch of or's is gonna have to test all 5 million products.
>
>I wonder if there is a way we can treat this like a two step process.
>
>1) cut down the number of products
>
>2) sort them by #matches, popularity, etc
>
>You've talked about #2, but how about #1. Is there any way to either include
>or exclude a product? Users don't just ask for red, they ask for "tires
>(maybe red)". Not all 5 million products are tires, right?
>
>-Andy
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