Sphinx – A Use case with Rails 3

Sphinx is open source search server used for full text search, we have used it with Rails and MySql database.

Why Sphinx:

• Blazingly fast indexing and searching
• Variety of Text Processing features which are easy to adapt as per Application.
• Scalling: It can scale up to millions of queries per day.
• Performance: Sphinx indexes up to 10-15 MB of text per second per single CPU core.
• Easy to write Sql Style Queries
• Grouping and Clustering
• Distrubuted Searching

Thinking Sphinx: Thinking Sphinx is a Ruby gem which helps us to connect Sphinx with Rails Active Record.
We can attach our models to sphinx through Thinking Sphinx

Example:

Suppose we have Model Country with  fields: id, name, about, continent_id, capital, rating_no

class Country < ActiveRecord::Base
has_many :places_to_visits
end

PlacesToVisit
field: name, country_id

class PlacesToVisit < ActiveRecord::Base
belongs_to :country
end

We want to have full text search on all fields of Country except id and its places to visit (has many association)

How to Use:
We will write in  Country model

you can read more about indexing here
http://freelancing-god.github.com/ts/en/indexing.html

Searching example

Suppose we want to search countries with rating between 5 and 10.

Country.search params[:search], :with => {:rating_no => 5..10}

Here with is used for filtering, it accepts ruby array and ranges

A typical example with some advanced options

• We have provided field weights here so that while searching is applied name will have more priority than about
• conditions is for full text searching specific attributes, :with is for filtering search results.
• We use pagination with incorporating :page and :per_page parameters
• match mode: How the key words will match to the fields
• :all – all records that has the complete key word will be returned
• :any – means all records that has any of the keyword will be returned
• :boolean – we can also use boolean operators with keywords
• example: Country.search ‘India | USA’, :match_mode => :boolean