Completion suggester in Elasticsearch - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Completion suggester in Elasticsearch?

The Completion suggester helps provide fast autocomplete or search-as-you-type functionality by suggesting possible completions for a given prefix.

beginner

Which field type must be used in the mapping to enable the Completion suggester?

The field must be mapped as completion type to enable the Completion suggester functionality.

intermediate

How do you define a Completion suggester query in Elasticsearch?

You define it inside the _search request under the suggest section, specifying the field, prefix, and size of suggestions.

intermediate

What is the difference between prefix and regex in Completion suggester queries?

prefix matches suggestions starting with the given text, while regex allows pattern matching for more flexible suggestions.

advanced

Why is the Completion suggester faster than a regular prefix query?

Because it uses a specialized data structure called a FST (Finite State Transducer) optimized for prefix lookups, making suggestions very fast.

Which field type enables the Completion suggester in Elasticsearch?

A completion

B text

C keyword

D integer

Only the 'completion' field type supports the Completion suggester functionality.

Where do you specify the Completion suggester in an Elasticsearch search request?

A In the 'aggs' section

B Inside the 'query' section

C In the 'sort' section

D Under the 'suggest' section

The Completion suggester is defined inside the 'suggest' section of the search request.

What does the 'prefix' parameter do in a Completion suggester query?

A Matches suggestions containing the prefix anywhere

B Matches suggestions ending with the prefix

C Matches suggestions starting with the prefix

D Matches suggestions exactly equal to the prefix

'prefix' matches suggestions that start with the given text.

Which data structure does the Completion suggester use for fast lookups?

A Linked List

B Finite State Transducer (FST)

C Binary Search Tree

D Hash Table

The Completion suggester uses a Finite State Transducer (FST) for efficient prefix matching.

Can the Completion suggester handle fuzzy matching by default?

A No, it only supports exact prefix matching

B Yes, it supports fuzzy matching by default

C Only if 'fuzzy' parameter is set to true

D Only with regex patterns

The Completion suggester does not support fuzzy matching by default; it matches exact prefixes.

Explain how to set up and use the Completion suggester in Elasticsearch.

Think about mapping, indexing, and querying steps.

Describe why the Completion suggester is efficient for autocomplete compared to regular text queries.

Focus on data structure and performance.