# Product Search Engine Design with Sphinx and Faceted Search

**URL:** <https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772>\
**Category:** Rails\
**Created:** [May 25, 2009, 5:26pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772 "2009-05-25T17:26:42Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![winsmith](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/a698b9/32.png) [@winsmith](https://www.ruby-forum.com/u/winsmith)\
**Post date:** [May 25, 2009, 5:26pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772/1 "2009-05-25T17:26:42Z")

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Hi, this is my first question on this forum! Please, take some time to  
read this message, since it is very big. (sorry)

I’m building a search engine (crawler) that indexes products data from  
more than 500 online brazilian stores. This part is easy =\> Crawling,  
Extracting Information, etc.

I’m running on an app design problem. Different types of products have  
different attributes. For instance: Books have :Publisher, :Edition,  
:Author, etc… Digital Cameras have :Brand, :Megapixel, etc… and so  
on. I REFUSE MYSELF TO CREATE ONE MODEL FOR EVERY TYPE OF PRODUCT.

The crawler automatically discover the types of products and product  
attributes per type of product. What I was thinking is to have only one  
model =\> Product. Please see below the design I want to have (if you  
have any suggestions, please, tell me).

class Category \< ActiveRecord::Base  
end

class Product \< ActiveRecord::Base  
belongs\_to :category  
end

class AttributeType \< ActiveRecord::Base  
belongs\_to :category  
end

class Attribute \< ActiveRecord::Base  
belongs\_to :product  
belongs\_to :attribute\_type  
end

The Category model represents the type of product (Books, Digital  
Camera) and each category has an Attribute Type set. My application is  
just like [http://www.pricejunkie.com](http://www.pricejunkie.com) but specially for brazilian  
customers. The customer will be presented with a search field (Sphinx  
with Thinking Sphinx or UltraSphinx) and a list of categories.

What exactly is my problem?? Thinking Sphinx FACETS (filters). In this  
applications, each facet is an Attribute Type. Please see  
[http://www.pricejunkie.com](http://www.pricejunkie.com), click on the Book category and you will see  
what I mean.

The problem is that facets in Thinking Sphinx are defined per model  
field. If I had a Book model with the field :autor, I could just do this  
with Thinking Sphinx on the Book model:

define\_index do  
indexes author, :facet =\> true  
end

I need my system to have dynamic facets per product category, otherwise  
I will have to create more than 300 different product types…

I hope I made myself clear. PLEASE SOMEONE HELP.  
Thanks

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<div class="post-metadata">

**Author:** ![winsmith](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/a698b9/32.png) [@winsmith](https://www.ruby-forum.com/u/winsmith)\
**Post date:** [May 25, 2009, 5:55pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772/2 "2009-05-25T17:55:23Z")

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I think there may be something wrong with your model. Firstly I think  
you  
need  
Category  
has\_many :products  
has\_many :attribute\_types

Product  
belongs\_to :category  
has\_many :attributes

AttributeType  
belongs\_to :category  
has\_many :attributes

Attribute  
belongs\_to :product  
belongs\_to :attribute\_type

Is there a problem with the above? If one has a product then  
product.category.attribute types will give one a collection of attribute  
types relevant to that model. One could also use product.attributes to  
get  
a collection of attributes, but since each attribute has an associated  
attribute type one can also get the attribute types for a product by  
this  
route. I am no database expert, so I may be wrong, but I suspect that  
it is  
not a good idea to have two separate relationship routes between models  
like  
this.

My other problem is that I am not sure what you are trying to achieve.  
Can  
you explain in a couple of sentences what data you wish to extract when  
the  
user clicks on the Book category for example?

Colin

2009/5/25 Daniel J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

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<div class="post-metadata">

**Author:** ![winsmith](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/a698b9/32.png) [@winsmith](https://www.ruby-forum.com/u/winsmith)\
**Post date:** [May 25, 2009, 6:32pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772/3 "2009-05-25T18:32:50Z")

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Hi thank you for your answer

The models you wrote are ok, I just simplified them for illustration  
purposes.

My problem is with search facets (filtering) using Thinking Sphinx.  
Suppose that I had a book model with the fields author, publisher and  
year. When a customer select the book category, he will be presented  
with a list of books and on the left side, he will have the “facets”  
like that:

authors  
-author 1 (203)  
-author 2 (125)  
-author 3 (99)  
-author 4 (38)  
…

publishers  
-publisher1 (199)  
-publisher1 (21)  
-publisher1 (408)  
-publisher1 (134)  
…

years  
-2009 (109)  
-2008 (33)  
-2007 (12)  
-2006 (500)  
…

This would be very easy if I had a book model. Thinking Sphinx requires  
a facet to be defined like this on the “book” model:

define\_index do  
indexes author, :facet =\> true  
indexes publisher, :facet =\> true  
indexes year, :facet =\> true  
end

THE PROBLEM IS THAT I DO NOT HAVE THIS MODEL AND THIS ATTRIBUTES  
DEFINED. I don’t have this defined because I would have to know all the  
product types and all the possible attributes for each product type and  
create a different model for each product type.

* * *

## WHAT IM LOOKING FOR

I’M LOOKING FOR SOME KIND OF METAPROGRAMMING THAT ENABLES ME TO FIND  
WHAT ARE THE ATTRIBUTE TYPES FOR A CATEGORY OF PRODUCTS AND BUILD THE  
FACETS AT RUNTIME. SOMETHING LIKE THIS IN MY PRODUCT MODEL:

define\_index do  
find whatever attribute types are relevant for this category  
and makes it :facet =\> true  
end

THANKS!!

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<div class="post-metadata">

**Author:** ![winsmith](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/a698b9/32.png) [@winsmith](https://www.ruby-forum.com/u/winsmith)\
**Post date:** [May 25, 2009, 8:09pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772/4 "2009-05-25T20:09:49Z")

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On Monday 25 May 2009, Daniel J. wrote:

> types…  
> I have never used Thinking Sphinx or even plain Sphinx, still, here are  
> my 2¢:

It seems to me that your problem is that you have a meta-model toolkit  
on the one hand, your Category, Product, AttributeType, and Attribute  
classes. While on the other hand, you want to define concrete facets  
such as author, brand, etc. on top of that. That may be possible, but  
probably it is not.

I’ve had a quick look at the code for Thinking Sphinx and you’ll  
probably be able to find what you need if you start studying it closely  
starting from its ActiveRecord integration. I don’t think you will be  
able to achieve your goal without understanding details of how Thinking  
Sphinx works, as you’re trying to stretch it beyond its intended use.

Michael

–  
Michael S.  
[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
[http://www.schuerig.de/michael/](http://www.schuerig.de/michael/)

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<div class="post-metadata">

**Author:** ![winsmith](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/a698b9/32.png) [@winsmith](https://www.ruby-forum.com/u/winsmith)\
**Post date:** [May 25, 2009, 6:53pm UTC](https://www.ruby-forum.com/t/product-search-engine-design-with-sphinx-and-faceted-search/168772/5 "2009-05-25T18:53:30Z")

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I understand. Sorry, I do not know enough about how the inner workings  
of  
Sphinx to be able to help.

Can anyone else help?

Colin

2009/5/25 Daniel J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)