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![QUICK START def index @q = Document.ransack(params[:q]) @documents = @q.result(distinct: true) end <%= search_form_for @q do |f| %> <%= f.label :title_cont %> <%= f.search_field :title_cont %> <%= f.submit %> <% end %> SELECT * FROM documents WHERE title ILIKE '%title%'; Executes:](https://image.slidesharecdn.com/textsearch-170828170955/75/Solving-text-search-problems-with-Ruby-on-Rails-28-2048.jpg)
![HOWTO SPEED UPTHE SEARCH? (in PostgreSQL + Ruby on Rails) class IndexDocuments < ActiveRecord::Migration[5.1] def change enable_extension 'pg_trgm' add_index(:documents, 'title gin_trgm_ops', using: :gin) end end](https://image.slidesharecdn.com/textsearch-170828170955/75/Solving-text-search-problems-with-Ruby-on-Rails-31-2048.jpg)
Solving text search problems with Ruby on Rails
- 1. SOLVINGTEXT SEARCH PROBLEMS WITHRUBY ON RAILS by Andrii Gladkyi
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- 3. ME • 15 yearsof dev experience • Desktop (Delphi/C#/C++) • Web (Ruby/JavaScript) • 5 Ruby projects having text search solutions
- 4. AGENDA • Full textsearch • Phrase match • Filters/Facets
- 5. FULLTEXT SEARCH • Searchfor a phrase within document • Partial matches • Order by relevance • Phrase highlights • Similar matches • Typos correction
- 6. SOLUTIONS • RDBMS search •Sphinx • ElasticSearch
- 7. RDBMS SEARCH • Noexternal dependencies • Relatively slow • Provides only basic FTS features (PostgreSQL)
- 8. EXAMPLE ALTER TABLE documentsADD COLUMN fts_col tsvector; CREATE INDEX fts_idx ON documents USING GIN (fts_col); UPDATE documents SET fts_col = to_tsvector(title || ' ' || content); SELECT * FROM documents WHERE fts_col @@ to_tsquery('text to find'); Requirement: Search within document's title and content Implementation:
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- 10. PG_SEARCH HIGHLIGHTS • Activelymaintained • 99% test coverage • Dependencies:ActiveRecord 4.2+,ActiveSupport • Single/multimodel search
- 11. QUICK START class Document< ActiveRecord::Base include PgSearch pg_search_scope :search_full_text, against: { title: 'A', content: 'B' } end Document.search_full_text('text to find') Single model search
- 12. REVIEW • Simple setup •No external dependencies • AR-compatible output • PostgreSQL extensions • Order by relevance • PostgreSQL only :) • Multimodel indexex need to be rebuilt • Only basic FTS features Pros: Cons:
- 13. SPHINX SEARCH ENGINE •RDBMS connections • MySQL storage engine option • SQL-like queries • Facets
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- 15. THINKING_SPHINX HIGHLIGHTS • Verymature (~10 years) project • Supports ActiveRecord 3.1+ • Well documented • Requires mysql gem to be installed
- 16. QUICK START ThinkingSphinx::Index.define :document,with: :real_time do indexes title indexes content end after_save ThinkingSphinx::RealTime.callback_for(:document) rake ts:regenerate Document.search('text to find')
- 17. REVIEW • Field weights •Facets • Advanced filters • Different indexing strategies (realtime and SQL) • Deltas for SQL-backed indexes • Delta indexes may cause data inconsistency Pros: Cons:
- 18. ELASTICSEARCH ENGINE • RESTHTTP interface • Scalable • Aggregations • Powerful mappings
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- 20. SEARCHKICK HIGHLIGHTS • Developedfor own needs • AR-like query language • Supports ActiveModel 4.1+ • Zero downtime reindex
- 21. QUICK START class Document< ActiveRecord::Base searchkick end Document.reindex Document.search('text to find')
- 22. REVIEW • Tons offeatures • Bulk document updates • Autocomplete • Facets • Very opinionated development • Documentation issues • Default setup doesn't match any practical requirements... • ... therefore a reconfiguration is a must Pros: Cons:
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- 24. CONCLUSION • Use RDBMSsearch for a simple search within a small and defined set of documents • Want to scale/advanced features - try ElasticSearch or Sphinx
- 25. PHRASE MATCH • Searchby exact name • No irrelevant matches
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- 27. RANSACK HIGHLIGHTS • Workson the top of RDBMS search/filtering • Case insensitive match by default • Able to build search forms • Rails 3-5.1 compatible
- 28. QUICK START def index @q= Document.ransack(params[:q]) @documents = @q.result(distinct: true) end <%= search_form_for @q do |f| %> <%= f.label :title_cont %> <%= f.search_field :title_cont %> <%= f.submit %> <% end %> SELECT * FROM documents WHERE title ILIKE '%title%'; Executes:
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- 30. HOWTO SPEED UPTHESEARCH? (in PostgreSQL)
- 31. HOWTO SPEED UPTHESEARCH? (in PostgreSQL + Ruby on Rails) class IndexDocuments < ActiveRecord::Migration[5.1] def change enable_extension 'pg_trgm' add_index(:documents, 'title gin_trgm_ops', using: :gin) end end
- 32. REVIEW • Search/filter forms •Simple AR-compatible interface • Sort helpers • Powerful matches • Good documentation • Memory consumption issues • No out-of-box ranking (may be implemented manually) Pros: Cons:
- 33. FACETS • Hide irrelevantfacets • Count documents • Filter by facet value
- 34. FACETS IMPLEMENTATION • Sphinx,ElasticSearch - built in • Must implement manually when RDBMS search
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