Searching content should be fast and easy. Today everyone is used to the simplicity and speed of the Google search where the user can type everything into a single input field. Nobody wants to face a complex input mask where he has to think how to correctly search for the content he wants to find. That’s why in this talk we will present Elasticsearch, the full-featured full-text search engine that can be used and configured the way you want to. We will show you the most important parts, tips and tricks when building our own search and some lessons learned from our experiences.

1. Building a Full-Featured
Full-Text Search using
Elasticsearch
SFSCon - Free Software Conference 2019
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2. About me
Alex Lanz
2https://aboutbits.it
● Co-Founder @ AboutBits
● Software Developer
@about_bits
@alex__lanz

3. Shay Banon - Creator of Elasticsearch
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Search is something that any application should
have.
https://thedudeabides.com/articles/the_future_of_compass

4. 4https://airbnb.com

5. 5https://twitter.com

6. 6https://support.apple.com/en-gb/HT201732

7. But how can I develop a
search functionality?
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8. Elasticsearch
Search Engine
● Based on the Lucene library
● HTTP web interface (REST)
● Schema-free JSON documents
● Distributed architecture
● High scalability
● Open Source
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https://www.elastic.co/products/elasticsearch

9. Check out the docs!
https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html
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10. Storytelling!
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11. Different words
Example
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14. Different words
Solution
Synonyms
● Replaces or adds additional
words (tokens)
● During text analysis
schlagobers => sahne
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https://www.elastic.co/guide/en/elasticsearch/reference/7.4/analysis-synonym-tokenfilter.html

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16. Compound words
Example
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19. Compound
words
Solution
ngrams
● Contiguous sequence of n items
from a given word (term)
● Useful for languages that don’t
use spaces or that have long
compound words
Apfelsaft: apf, pfe, fel, els, lsa, saf,
aft
Apfel: apf, pfe, fel
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https://www.elastic.co/guide/en/elasticsearch/reference/7.4/analysis-ngram-tokenizer.html

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21. Not enough words
Example
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24. Not enough
words
Solution
Boosting
● Control the relevance of a search
● Increase (or decrease) the
relative weight of a clause
Boost of 2 for products within the
category “Obst”.
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https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-term-query.html

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27. Enriched results
Example
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28. 28https://booking.com

29. Enriched results
Solution
Aggregations
● Provide aggregated data based
on a search query
● Analytic information over a set of
documents
● All with one query
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https://www.elastic.co/guide/en/elasticsearch/reference/7.4/search-aggregations.html

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31. Elasticsearch
Pro Tipps
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32. Elasticsearch
Pro Tipps
● It’s an enhancement not a
replacement for a SQL database
● Data must no be persisted
forever, rebuild the index if
necessary
● Denormalize your data
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33. Questions?
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