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PERF: optimise and improve topic similarity search

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FIX: shows up similarity search with blank results
This commit is contained in:
Sam
2014-08-08 12:12:53 +10:00
parent f20c5a02c7
commit 16b7004767
5 changed files with 56 additions and 16 deletions
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35
app/models/topic.rb
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@ -363,21 +363,38 @@ class Topic < ActiveRecord::Base
return [] unless title.present?
return [] unless raw.present?
similar = Topic.select(sanitize_sql_array(["topics.*, similarity(topics.title, :title) + similarity(p.raw, :raw) AS similarity", title: title, raw: raw]))
.visible
.where(closed: false, archived: false)
.secured(Guardian.new(user))
.listable_topics
.joins("LEFT OUTER JOIN posts AS p ON p.topic_id = topics.id AND p.post_number = 1")
.limit(SiteSetting.max_similar_results)
.order('similarity desc')
filter_words = Search.prepare_data(title + " " + raw[0...200]);
ts_query = Search.ts_query(filter_words, nil, "|")
# Exclude category definitions from similar topic suggestions
candidates = Topic.visible
.secured(Guardian.new(user))
.listable_topics
.joins('JOIN posts p ON p.topic_id = topics.id AND p.post_number = 1')
.joins('JOIN post_search_data s ON p.id = s.post_id')
.where("search_data @@ #{ts_query}")
.order("ts_rank(search_data, #{ts_query}) DESC")
.limit(SiteSetting.max_similar_results * 3)
exclude_topic_ids = Category.pluck(:topic_id).compact!
if exclude_topic_ids.present?
similar = similar.where("topics.id NOT IN (?)", exclude_topic_ids)
candidates = candidates.where("topics.id NOT IN (?)", exclude_topic_ids)
end
candidate_ids = candidates.pluck(:id)
return [] unless candidate_ids.present?
similar = Topic.select(sanitize_sql_array(["topics.*, similarity(topics.title, :title) + similarity(topics.title, :raw) AS similarity", title: title, raw: raw]))
.joins("JOIN posts AS p ON p.topic_id = topics.id AND p.post_number = 1")
.limit(SiteSetting.max_similar_results)
.where("topics.id IN (?)", candidate_ids)
.where("similarity(topics.title, :title) + similarity(topics.title, :raw) > 0.2", raw: raw, title: title)
.order('similarity desc')
similar
end