The postgres trigram module (https://www.postgresql.org/docs/9.6/pgtrgm.html) is used for various kind of text search applications. A good chunk of it is supported in CockroachDB 22.2 (see below list of functionality), but not everything yet.

Supported in CockroachDB 22.2:

• similarity(), show_trgm()
• text % text
• pg_trgm.similarity_threshold
• trigram gin inverted indexes
• Accelerate %
• Accelerate LIKE and ILIKE

Not yet supported:

• Implement word_similarity()
• Implement strict_word_similarity()
• Implement %> and <% (word similarity search)
• Accelerate %> and <%
• Implement <<% and %>> (strict word similarity search)
• Acclerate %>> and <<%
• Implement <->, <<->, <->>, <<<->, and <->>> (distance, word similarity, and strict word similarity operators. Note that they do not get accelerated in PG at all.)
• Accelerate regex match
• trigram operators and functions, like % and show_trgm, on collated string types

Jira issue: CRDB-5466
Epic: CRDB-15016