How to install the additional module pg_trgm

Question

I just want to know how to install the module pg_tgrm as used in the trigram indexing scheme that allows you to do un-anchored search patterns on an index.

WHERE foo LIKE '%bar%';

Answer 1

pg_trgm is an extension, so:

CREATE EXTENSION pg_trgm;

If you get the following error

ERROR: could not open extension control file ".../extension/pg_trgm.control":
No such file or directory"

then you need to install the module for your operating system

• Ubuntu/Debian:

  sudo apt install postgresql-contrib
  

• Redhat/Centos

  sudo dnf install postgresql10-contrib
  

• Fedora

  sudo dnf install postgresql-contrib
  

Answer 2

1) Log into postgres

psql -U <DB_USERNAME>

2) After you are connected, switch to the DB you want to install the extension for:

\c <DB_NAME>

3) Then install the extension as answered previously:

CREATE EXTENSION pg_trgm;

Installing the extension initially gave me issues because I was not doing step 2. I thought the installation was a global thing but it seems its per DB

Answer 3

To complete the answer of @Jendrusk for :

• CentOs system you can also use

yum install postgresql-contrib