What is the purpose of the PG TRGM module?
The pg_trgm module provides GiST and GIN index operator classes that allow you to create an index over a text column for the purpose of very fast similarity searches. These index types support the above-described similarity operators, and additionally support trigram-based index searches for LIKE , ILIKE , ~ and ~* queries.
How is trigram matching used in full text index?
Trigram matching is a very useful tool when used in conjunction with a full text index. In particular it can help to recognize misspelled input words that will not be matched directly by the full text search mechanism. The first step is to generate an auxiliary table containing all the unique words in the documents:
How to use trigram matching in PostgreSQL?
The pg_trgm module provides functions and operators for determining the similarity of alphanumeric text based on trigram matching, as well as index operator classes that support fast searching for similar strings. F.31.1. Trigram (or Trigraph) Concepts
The pg_trgm module provides GiST and GIN index operator classes that allow you to create an index over a text column for the purpose of very fast similarity searches. These index types support the above-described similarity operators, and additionally support trigram-based index searches for LIKE, ILIKE, ~ and ~* queries.
How to instal PG-TRGM on Windows [ step by step guide ]?
Another way to do it is via pgAdmin : Right-click on Extensions and select New Extension… Choose your extension from the drop-down menu in the Name field and click OK. Thanks for contributing an answer to Geographic Information Systems Stack Exchange!
Is the PG-trgm extension available in PostgreSQL 9.5?
The pg_trgm extension should already be available with PostgreSQL 9.5 on Windows (supposing you installed via the official installer). This means that there is no need to install it, however you need to activate it in each database that need to use it. The only thing left to activate it should be to run the following SQL code:
When does true return true in PG TRGM?
Returns true if the similarity between the trigram set in the first argument and a continuous extent of an ordered trigram set in the second argument is greater than the current word similarity threshold set by pg_trgm.word_similarity_threshold parameter. Commutator of the <% operator.