Synonym handling in Elasticsearch - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is synonym handling in Elasticsearch?

Synonym handling in Elasticsearch means telling the search engine that some words mean the same. This helps find more results even if the exact word isn't used.

beginner

How do you define synonyms in Elasticsearch?

You define synonyms by creating a synonym filter in the analyzer settings. You list words or phrases that should be treated as equal, separated by commas or arrows (=>).

intermediate

What is the difference between 'synonym' and 'synonym_graph' filters?

'synonym' filter works well for indexing but can cause issues with phrase queries. 'synonym_graph' is better for search time and phrase queries because it handles word positions correctly.

intermediate

Why is it important to apply synonyms at search time rather than index time?

Applying synonyms at search time keeps the index smaller and more efficient. It also allows changing synonyms without reindexing all data.

beginner

Give an example of a synonym rule in Elasticsearch.

Example: "car, automobile, vehicle" means these words are treated the same. Another example: "usa, united states, america" means all these refer to the same concept.

What does a synonym filter do in Elasticsearch?

A Deletes duplicate documents

B Treats listed words as equal during search or indexing

C Sorts search results alphabetically

D Encrypts the search data

A synonym filter makes Elasticsearch treat certain words as the same to improve search results.

Which synonym filter is better for phrase queries?

A synonym_graph

B synonym

C stop

D lowercase

The synonym_graph filter handles word positions properly, making it better for phrase queries.

Where is it recommended to apply synonyms for flexibility?

A In the database

B At index time

C In the client application

D At search time

Applying synonyms at search time allows changing them without reindexing data.

How are synonyms usually listed in the filter?

A As XML tags

B In JSON arrays

C Separated by commas or arrows

D In SQL tables

Synonyms are listed as comma-separated or arrow-separated words or phrases.

What is a benefit of using synonym handling?

A Finds more relevant search results

B Speeds up indexing

C Reduces disk space

D Prevents spelling mistakes

Synonym handling helps find more relevant results by matching similar words.

Explain how to set up synonym handling in Elasticsearch and why it is useful.

Think about how you tell Elasticsearch that some words mean the same.

Describe the difference between applying synonyms at index time versus search time.

Consider when the synonym rules are applied and how it affects the data.