Full-text search

Perform a full-text search

A full-text search finds words or phrases within larger texts. You can search within a specific text field or across all text fields.

This article provides a good overview of the most relevant full-text search capabilities. Please find further details about all the full-text search features in the reference documentation.

The examples in this article use a schema with the following fields:

Single word

To search for a word (or word stem) across all text fields, you can construct the following simple query:

FT.SEARCH index "word"

Instead of searching across all text fields, you might want to limit the search to a specific text field.

FT.SEARCH index "@field: word"

Words that occur very often in natural language, such as the or a for the English language, aren't indexed and will not return a search result. You can find further details in the stop words article.

The following example searches for all bicycles that have the word 'kids' in the description:

FT.SEARCH idx:bicycle "@description: kids"

Phrase

A phrase is a sentence, sentence fragment, or small group of words. You can find further details about how to find exact phrases in the exact match article.

Word prefix

You can also search for words that match a given prefix.

FT.SEARCH index "prefix*"

FT.SEARCH index "@field: prefix*"

Here is an example that shows you how to search for bicycles with a brand that starts with 'ka':

FT.SEARCH idx:bicycle "@model: ka*"

Word suffix

Similar to the prefix, it is also possible to search for words that share the same suffix.

FT.SEARCH index "*suffix"

You can also combine prefix- and suffix-based searches within a query expression.

FT.SEARCH index "*infix*"

Here is an example that finds all brands that end with 'bikes':

FT.SEARCH idx:bicycle "@brand:*bikes"

Fuzzy search

A fuzzy search allows you to find documents with words that approximately match your search term. To perform a fuzzy search, you wrap search terms with pairs of % characters. A single pair represents a (Levenshtein) distance of one, two pairs represent a distance of two, and three pairs, the maximum distance, represents a distance of three.

Here is the command that searches across all text fields with a distance of one:

FT.SEARCH index "%word%"

The following example finds all documents that contain a word that has a distance of one to the incorrectly spelled word 'optamized'. You can see that this matches the word 'optimized'.

FT.SEARCH idx:bicycle "%optamized%"

If you want to increase the maximum word distance to two, you can use the following query:

FT.SEARCH idx:bicycle "%%optamised%%"